ADB not working, but Fastboot is
Flash ROM with Fastboot

Before starting ensure bootloader is unlocked. Obtain a ROM of your choice, and note the location on your computer.


Reboot your device into fastboot mode via one of the following options.


adb reboot bootloader (requires USB debugging to be turned on). - for working adb; OR
power off the device then back on with 'vol up' + power button. - for nonworking adb

Wipe your device. fastboot -w
Update your ROM. fastboot update /path/to/your/RomFile.zip
Your phone will update and automatically reboot into the new ROM




Edit:

Try the Universal Naked Drivers by 1wayjohnny over at xda forums.

This has been included because my researching has also found corrupted drivers can be the culprit

Try http://code.google.com/p/boot-unlocker-gnex/ to reset tamper flags.



The only other information I could find for the error: device not found is not helpful in this forum. It does lead towards development and programming though.