I've been watching the AVG Free forum on this topic,and there seems to be alot of issues with the AVG Free 7.5 upgrade/install.
Grisoft recommends a "repair" install,but here is a quote from one of the Moderators dated Oct 30,06:
QUOTE
Now, I actually prefer to uninstall / reinstall because it will give you additional options but if you had to setup the settings differently than the defaults you would have to repeat that using these instructions.
1. Download the latest AVG Free installation package from [free.grisoft.com]
2. Run the AVG Free install file
3. Choose the Uninstall option and follow the setup wizard, when you get to the part to remove user settings, select it.
4. Restart your computer then...
5. Now reinstall AVG using the setup file you got in step 1 and update it.
There are also
alot of posts about updating problems with AVG 7.5.
Being on dial up,I'm in no hurry!