The recent AVG 2011 update 3292, is cumbersome for Windows 7 64-bit OS customers because after getting this update you are unable to boot to your operating system. Certainly, AVG has got hold of this serious problem and issued a fix for the same.
Read the tips or watch the step-by-step video guide below to fix this issue:
Tips for users affected by AVG 271.1.1/3292 (432/3292) definition update:
- Users who have downloaded the 3292 update, prompted for a restart, but did not restart their system, please download fixcorex utility and run it. After running this utility it is safe to restart your computer.
- Users who have downloaded the update and applied the system restart should follow the instructions provided in this official tutorial.
- Users who are running Windows 7 and have not downloaded and installed this update  are ok and no action is necessary.
Source: AVG official blog