unlock the iphone, and see if it pop up with 'Trust this Computer"

1. Update iTunes
Check that you have the latest version of iTunes installed on your computer. In iTunes, select Check for updates in the Help menu.

2. Check the USB cable
Verify that the 30-pin to USB cable or Lightning Connector to USB cable is free of debris and not damaged. If another cable is available, test with that cable instead.

3. Verify that Apple Mobile Device Support is installed
iOS devices require Apple Mobile Device Support, which should be automatically installed with iTunes. To verify whether it is installed, follow the steps appropriate for your Windows operating system below.

Windows XP: Click Start and choose Control Panel. Open the "Add or Remove Programs" control panel and verify that Apple Mobile Device Support is visible in the list of currently installed programs.
Windows Vista and Windows 7: Click Start and choose Control Panel. Click "Uninstall a program" (or if using Windows Vista's Classic View of the Control Panel, click "Programs and Features"). Verify that Apple Mobile Device Support is visible in the list of currently installed programs.
Windows 8: Move the cursor to the upper right corner, click the magnifying glass, type Control Panel, and press Return. Click "Uninstall a program". Verify that Apple Mobile Device Support is visible in the list of currently installed programs.
If Apple Mobile Device Support is not listed, remove iTunes, QuickTime, Apple Software Update, Apple Application Support, and then reinstall iTunes. Follow the steps appropriate for your Windows operating system below:

Reinstall iTunes for Windows XP
Reinstall iTunes for Windows Vista, Windows 7, or Windows 8
If after reinstalling iTunes Apple Mobile Device Support is still not installed, follow steps in Trouble installing iTunes or QuickTime for Windows.

4. Restart the Apple Mobile Device Service
Follow the steps in How to restart the Apple Mobile Device Service (AMDS) on Windows to restart the Apple Mobile Device Service.
5. Verify that the Apple Mobile Device USB Driver is installed
For Windows XP
Connect the device to the computer.
Quit iTunes if it launches.
In the Start menu, right-click My Computer and choose Properties.
Click the Hardware tab, then click the Device Manager button. The Device Manager window should open.
Click the plus (+) icon next to Universal Serial Bus controllers to expand this selection.

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Locate the Apple Mobile Device USB Driver in this list. If this entry is displayed without any "x", "!" or "?" symbols over it, then this driver is successfully installed. Proceed to the next section, titled "Check for third-party software conflicts".
If the Apple Mobile Device USB Driver is not listed, proceed to the section below titled "If the Apple Mobile Device USB Driver is not listed".
If the Apple Mobile Device USB Driver is listed, but has a red "X" appearing next to the device's entry, this device is disabled. To enable this device, right-click its entry in Device Manager and choose Enable from the shortcut menu.

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f the Apple Mobile Device USB Driver entry is listed, but has an exclamation mark or question mark over it, continue to the next steps to reinstall the Apple Mobile Device driver.
Reinstall the Apple Mobile Device Driver

Right-click the Apple Mobile Device entry in Device Manager and choose Uninstall from the shortcut menu.
In the resulting dialog box, click OK.
In the Device Manager window, right-click Universal Serial Bus controllers and choose Scan for hardware changes from the shortcut menu.

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Click the Have Disk button. Note: If the Have Disk option is not present, choose a device category such as Mobile Phone or Storage Device if listed, and click next. Then the Have Disk button should appear.


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Click the Browse button, then navigate to the following location:
C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the usbaapl file.

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Click OK in the Have Disk window. Then click Next. Click Finish. Windows installs the driver.
Note: During installation, if a message appears stating that the software you are installing "has not passed Windows Logo testing", click Continue Anyway to continue installing the drivers.

For Windows Vista, Windows 7, and Windows 8
Connect the device to the computer.
Quit iTunes if it launches.
For Windows Vista and Windows 7:
Click the Start menu, right-click on Computer, and choose Properties.
In the upper-left corner, click Device Manager. The Device Manager window should open.
For Windows 8:
Move the cursor to the upper right corner, click the magnifying glass, type devmgmt.msc, and press Return. The Device Manager window should open.
Click the plus (+) icon (or disclosure triangle () (for Windows 7 and Windows 8) next to Universal Serial Bus controllers to expand this selection.

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[img]Locate the Apple Mobile Device USB Driver in this list. If this entry is displayed without any downward arrow, "!" or "?" symbols over it, then this driver is successfully installed. Proceed to the next section titled "Check for third-party software conflicts". If the Apple Mobile Device USB Driver is not listed, proceed to the section below titled "If the Apple Mobile Device USB Driver is not listed". A downward arrow appearing next to the device's entry in Device Manager indicates that this device is disabled. To enable this device, right-click its entry in Device Manager and choose Enable from the shortcut menu.[/img]


If the Apple Mobile Device USB Driver entry is listed, but has an exclamation mark or question mark over it, continue to the next steps to reinstall the Apple Mobile Device driver.
Reinstall the Apple Mobile Device Driver

Right-click the Apple Mobile Device entry in Device Manager and choose Uninstall from the shortcut menu.
When prompted, select the box "Delete the driver software for this device" and click OK.


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In the resulting dialog box, click OK.
In the Device Manager window, right-click Universal Serial Bus controllers and choose Scan for hardware changes from the shortcut menu.


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Windows automatically reinstalls the necessary drivers and attempts to remount the device.

If the Apple Mobile Device USB Driver entry still has an exclamation mark or question mark over it, right-click this entry and choose Properties. Under the General tab, look beneath "Device status."
If you see this error: "Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)," see the section below for Error Code 52.
If you see a different error code, continue to the next steps to manually update the Apple Mobile Device driver. You can find solutions to common errors and error code numbers in this Microsoft article. You may be instructed to reinstall the driver for this device. Follow the steps below to manually point to the usbaapl driver file.
Update the Apple Mobile Device Driver

Right-click the Apple Mobile Device entry in Device Manager and choose Update Driver Software.
Select "Browse my computer for driver software."
Select "Let me pick from a list of device drivers on my computer."


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Click the Have Disk button. Note: If the Have Disk option is not present, choose a device category such as Mobile Phone or Storage Device if listed, and then click next. The Have Disk button should then appear.


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Click the Browse button and navigate to C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the "usbaapl" file. (This file will be called "usbaapl64" if you have a 64-bit version of Windows. If you don't see "usbaapl64" here, or if there is no Drivers folder, look in C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers. instead).


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Click Open in the Have Disk window. Then, click Next and then Click Finish. Windows will install the driver.
Note: During installation, if a message appears stating that the software you are installing "has not passed Windows Logo testing," click Continue Anyway to continue installing the drivers.

Error Code 52

You may see this error in the Properties window for the device: "Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)."


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Install all available updates for Windows. See this Microsoft article for more information on how to do this.
Consult your computer manufacturer for updates for your computer's drivers, including disk drives, chipsets, and USB controllers.
Temporarily disable "forced driver signing enforcement" as follows:
Restart your computer.
While restarting, press the F8 key.
For Windows Vista and Windows 7:
For Windows 8:
The Windows Advanced Options list should appear. Press the Arrow Down key until "Disable forced driver signing enforcement" is highlighted.
Press the Return key.
Click "Change defaults or choose other options".
Click "Choose other options".
Click "Troubleshoot".
Click "Advanced options".
Click "Startup Settings".
Click "Restart" when prompted.
When prompted, press the 7 key to "Disable driver signature enforcement".
Reconnect the device.
Note: If the device is recognized successfully, then you'll need to perform these steps each time you start your computer. Consult Microsoft, or whoever supports the installation of Windows on your computer, for more troubleshooting to resolve the issue without having to select this option each time.
If the Apple Mobile Device USB Driver is not listed
Disconnect the device from the computer.
Save a screenshot by pressing the Home button and the Wake/Sleep button at the same time (the screen should flash briefly). Note: Taking screenshots and saving images on iPod touch requires iOS version 2.0 or later.
Reconnect the device to the computer.
Open the Device Manager in Windows as follows:
Windows XP: Click Start > Run. In the resulting dialog type devmgmt.msc and press Return.
Windows Vista or Windows 7: Click Start. In the dialog, type devmgmt.msc and press Return. If Windows needs your permission to continue, click "Continue".
Windows 8: Move the cursor to the upper right corner, click the magnifying glass, type devmgmt.msc, and press Return.
Expand all the sections labeled below (not all sections may be listed):
Imaging Devices
Other Devices
Portable Devices
Universal Serial Bus Controllers
Look for the entry that recognizes the device as a camera. This entry should be called Apple iPhone, Apple iPad, or Apple iPod.
If only "Unknown Device" appears

Right-click on the "Unknown Device" entry, and choose "Properties" from the shortcut menu.
Click the Details tab, and in the drop-down menu, select "Hardware IDs"
If the hardware ID displayed starts with this:
USB\VID_0000&PID_0000
This means that Windows cannot read the hardware IDs of the device, and so has replaced them with all zeros. This is typically caused by a faulty USB connection, or an incompatibility with your USB chipset drivers.
Disconnect the device, and unplug all USB devices from your computer. Shut your computer down, and power it back on.
Reconnect your device, testing each USB port for approximately 30 seconds to see if your device is recognized.
Test with an alternate, known-good 30-pin to USB cable or Lightning Connector to USB cable if available.
If you have an external USB 2.0 hub available, connect the hub to your PC, and then connect the iOS device to the hub.
If your device shows up in iTunes, try disconnecting the external USB 2.0 hub and connecting the iOS device directly to your PC. If the issue returns, you may need to use the external USB 2.0 hub as a temporary workaround. Then, consult your computer manufacturer for any updates for your USB chipset.
Note: If "Unknown Device" appears when connecting your device to more than 1 known-good computer, with more than 1 known-good USB cable, your device may require service. Contact Apple, or your wireless carrier, whichever provides phone support for your iPhone. To find Apple's contact information in your country, refer to Contacting Apple for Support and Service. If you use an iPhone, you can find your wireless carrier at Locating iPhone wireless carriers. Wherever you live in the world, you can find your device's service options at the Online Service Assistant. You may have questions about servicing your device, and you can find answers to frequent questions in this FAQ. If there is an Apple Retail Store nearby, find the closest store and then make a reservation through the online Apple Store Concierge. Reservations are strongly recommended.
If only Apple iPhone, Apple iPad, or Apple iPod appears

For Windows XP

Right-click the Apple iPhone, Apple iPad, or Apple iPod entry in Device Manager and choose Update Driver from the shortcut menu.
If asked to connect to Windows Update to search for software, choose "No, not this time" and click Next.
Choose "Install from a list or specific location (Advanced)" and click Next.
Choose "Don't search. I will choose the driver to install" and click Next.
Click the Have Disk button. (If the Have Disk option is not present, choose a device category such as Mobile Phone or Storage Device if listed, and click next. Then the Have Disk button should appear.) In the "Install from Disk" dialog, click the Browse button.
Navigate to C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the "usbaapl.inf" file, that is listed in this folder. Click OK on the "Install from Disk" dialog.
Click Next and finish the driver installation steps. Open iTunes to verify that the device is recognized properly.
For Windows Vista, Windows 7, or Windows 8

Right-click the Apple iPhone, Apple iPad, or Apple iPod entry in Device Manager and choose Update Driver from the shortcut menu.
Click "Browse my computer for driver software."
Click "Let me pick from a list of device drivers on my computer."
Click the Have Disk button. (If the Have Disk option is not present, choose a device category such as Mobile Phone or Storage Device if listed, and click next. The Have Disk button should then appear.)
In the "Install from Disk" dialog, click the Browse button.
Use this window to navigate to the following folder:
C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the "usbaapl" file. (This file will be called "usbaapl64" if you have a 64-bit version of Windows. If you don't see "usbaapl64" here, or if there is no Drivers folder, look in C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers. instead).
Click OK in the "Install from Disk" dialog.
Click Next and finish the driver-installation steps. Open iTunes to verify that the device is recognized properly.
If the device is not recognized while in Recovery Mode
Note: If your device is working on its own and is not in recovery mode, this set of steps is not for you; do not manually place the device into recovery mode.

Your device may not be recognized while in recovery mode. This can happen during an update or restore of your device. Typically when your device is in recovery mode, it will show the "Connect to iTunes" logo on its display. If iTunes does not recognize the device when in this state, try the following:

Open the Device Manager:
Windows XP: Click Start > Run. In the resulting dialog, type devmgmt.msc and press Return.
Windows Vista or Windows 7: Click Start. In the dialog, type devmgmt.msc and press Return on the keyboard. If Windows needs your permission to continue, click "Continue".
Windows 8: Move the cursor to the upper right corner, click the magnifying glass, type devmgmt.msc, and press Return.
Click the plus (+) icon (Windows XP and Vista) or the disclosure triangle () (for Windows 7 and 8) next to Imaging Devices, Other Devices, Portable Devices, and Universal Serial Bus Controllers to expand these sections.
Check these sections for one or more entries called Apple Mobile Device (Recovery Mode). These entries may or may not have exclamation marks on them similar to the following:


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If you see only one "Apple Mobile Device USB Driver" entry that has no errors on it:
Find out if the computer has USB 3.0 ports. Within Universal Serial Bus Controllers, locate any entries containing "USB 3.0" or "SuperSpeed USB" in the title. If these are listed, you have USB 3.0.
If you have USB 3.0
Try to connect the device to a different USB port. Try each port until the device is recognized. Some computers will have dedicated USB 2.0 and 3.0 ports. If so, a USB 2.0 port may resolve the issue.
Refer to your computer manufacturer for updates to the USB 3.0 chipset drivers.
If the issue persists, continue to the section titled "Check for third-party software conflicts".
If you do not have USB 3.0
Continue to the section titled "Check for third-party software conflicts".
If you see two "Apple Mobile Device (Recovery Mode)" entries with exclamation marks on them:
Open the Device Manager and connect your device. Click the View menu and select "Devices by connection".
Locate the erroneous "Apple Mobile Device (Recovery Mode)" entries. You may need to expand all sections of the Device Manager to see them.
Directly above these entries will be a USB Composite Device entry.


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Depending on your version of Windows, take the following steps to update this driver:
For Windows XP

Right-click the parent USB Composite Device entry and choose Update Driver from the shortcut menu.
If asked to connect to Windows Update to search for software, choose "No, not this time" and click Next.
Choose "Install from a list or specific location (Advanced)" and click Next.
Choose "Don't search. I will choose the driver to install" and click Next.
Click the Have Disk button. In the "Install from Disk" dialog, click the Browse button.
Use this window to navigate to the following folder: C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the usbaapl file, which is listed in this folder. Click OK on the "Install from Disk" dialog.
Click Next and finish the driver installation steps. Open iTunes to verify that the device is recognized properly, and continue restoring your device.
For Windows Vista, Windows 7, or Windows 8

Right-click the parent USB Composite Device entry and choose Update Driver Software from the shortcut menu.
Click "Browse my computer for driver software".
Click "Let me pick from a list of device drivers on my computer".
Click the Have Disk button. In the "Install from Disk" dialog, click the Browse button.
Use this window to navigate to the following folder:
C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers.
Double-click the "usbaapl" file. (This file will be called "usbaapl64" if you have a 64-bit version of Windows. If you don't see "usbaapl64" here, or if there is no Drivers folder, look in C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\Drivers. instead).
Click OK in the "Install from Disk" dialog.
Click Next and finish the driver-installation steps. Open iTunes to verify that the device is recognized properly, and continue restoring your device.
6. Check for third-party software conflicts
Certain phone and cellular device connectivity software from vendors such as Samsung, Nokia, Bora, Novatel, Sony, Android, LG, Sierra, Huawei, Pantech, or Motorola may cause your device not to be recognized. If you have such software on your computer:

Uninstall the phone or cellular connectivity software temporarily, and test. Contact the manufacturer of this software for assistance in doing this. If you use the third-party phone or cellular device for your Internet connection, try connecting to an alternate network using Wi-Fi or Ethernet.
Remove iTunes and all related Apple software by following this article (for Windows XP), or this article (for Windows Vista, Windows 7, and Windows 8).
After reinstalling iTunes, test the device.
If you still need your third-party phone or cellular connectivity software that was removed, reinstall this software and test your device to ensure it still functions with iTunes. Contact the vendor of your phone connectivity software if the issue returns.


I got this info from the Apple website. Just added it so it is easier.