I would recommend that you make sure avgcfgex is admin, but other than that nothing else is necessary. This sounds suspiciously like a bad install.
I would recommend you uninstall AVG using the
AVG removal tool. After removal, it will ask you to restart. Restart and then run the
YOP Removal Tool. Restart again, and then reinstall AVG.
If you still have the side-by-side error after this, then it's most likely a problem with the Visual C++ Package. To fix it use the file found
here (Vista 32bit) or
here (Vista 64bit).
Hopefully that will help!