Hey guys, Great news! After hours of playing around with iTunes and Windows I finally found a fix! I made an account on here just to share it with everyone. Feel free to copy this to other forums ect but please give credit. =] It turned out to be a driver issue, I don't know what causes this, but re-installing the iDevice drivers fixed the problem for me. In case you don't know how to re-install your iDevice drivers follow these simple steps and finally fix the trust this computer problem. Note: Windows 8.1 OS/iPhone 4S is used. IDK about drivers on Mac. Step 1: Make sure iTunes is closed and your iDevice is unplugged. Step 2: Navigate to Control Panel\Hardware and Sound\Devices and Printers (Or search for it) Step 3: Find your iDevice (In my case it was called "Apple iPhone") and right click it, click on properties. Step 4: Click on the Hardware tab up the top and click properties in the bottom right. This will open another properties box. Step 5: Click "Change settings" in the bottom left. Another properties box will open. Step 6: Click on the driver tab up the top and click on "Uninstall" at the bottom. Click "OK" to the warning to confirm driver uninstall. Step 7: Simply plug your iDevice into your computer and Windows will automatically re-install the fresh drivers and everything will now work!