I am using a SanDisk Cruzer 32 GB thumbdrive on a HP Multimedia PC with Windows 8 Pro and plenty of memory and disk space. I was able to backup my iPhone 4 with iOS 6.1 easily to iTunes 10.7. My phone was hooked up to the PC via my USB hub and was charging. When I placed the Cruzer in the USB hub, the Cruzer light began to flash as the drive communicated with the PC. At the same time, my iPhone 4 gave a “chirp,” and the initial screen with the battery level appeared. Then it went back to sleep. After this, i was unable to backup my iPhone 4 to iTunes 10.7. I get the following messages: (1) the PC cannot recognize the device that was connected, and (2) the iPhone 4 cannot cannot start a session with iTunes 10.7. Whenever the phone is plugged into the PC and I plug the Cruzer into the USB hub, the same thing happens. I tried deleting the driver for both devices, rebooting, and reinstalling the drivers. However, nothing has worked. Your help would be appreciated.
Does your system use something similar to this?