i thank that grisoft posted that up from novmber to the time that they stop supporting 7.1.
A recent AVG update can cause problems for users still using outdated versions of AVG (version 7.0 or 7.1), or if AVG Free was previously used on the same computer. Symptoms can vary from an incorrect state of some AVG components, to errors during running tests, causing AVG to unexpectedly close. Detailed description of these symptoms and information on how to correctly solve this problem is available at the Support section, topic no. 545.
545:Repetitive EXCEPTION error after the last AVG update
There may be a problem with some of the AVG Control Center components after the last AVG update. This problem appears only when a very old program (AVG 7.0) version is updated. The error messages may be related to
Virus Base component (incorrect state)
Shell Extension (not installed)
Resident Shield (not loaded or installed)
The solution is to do a Repair installation of your AVG using the latest AVG 7.5 installation file. This process is described in details in our FAQ 286.
If there was AVG Free installed on your pc in the past, it is necessary to follow also these steps after the repair installation: run AVG Control Center - Update Manager - Settings - tab URL - use button Default and confirm.
If the problem persists, please contact our technical support team either using our Technical Support form or directly at firstname.lastname@example.org (please enter your AVG license number (can be found in AVG - Information menu - About AVG) into the e-mail body).
Examples of possible error states:
Virus EXCEPTION found on Avgcore.dll, avgcc.exe files
Operating system reboots itself.
Error: Resident Shield is not loaded or installed
Internal virus base: "It is not possible to check the state of this component, connection failed." or "Component is installed properly, however the control failed with error code: 0x81000002"
AVG Shell Extension: AVG is not integrated in the Microsoft Windows Explorer.