- you uninstall AVG
- you restart Windows if prompted to do so
- you do some manual cleanup of AVG leftovers
- you run AVG’s cleanup tool
- you install AVG
- AVG works fine
- you shutdown and restart
- on next Windows session, AVG has vanished
If you run the AVG cleanup tool after uninstalling AVG (and perhaps being prompted to restart Windows) just before installing AVG, then install AVG, you won’t have been prompted to restart Windows between the cleanup and the new install. The cleanup works by seeding HKLM..RunOnce with an entry to uninstall AVG, which it does, the next time to shutdown and restart Windows – so it kills the new install you have just completed!
The bug may be that because the cleanup tool finds no active traces of AVG when it runs, it doesn’t see a need to prompt a restart of Windows. It then exits, so is no longer there to note the new material added by the fresh AVG installation.
There also may be a bug in the fresh (in my case, offline installer for AVG Free 2012 32-bit downloaded 19 August 2012) installer, if that fails to look for and detect the RunOnce entry created by the cleanup tool.
I’m fairly sure of the mechanism of this issue, because while still in Windows after installing AVG anew, I spent some time in Regedit and noted the RunOnce entry there. I’m also fairly sure this is not a malware effect, as the PC had not been online since formal scanning with a variety of antivirus rescue CD scanners (via Sardu) and other tools (via Bart).
However, a possible contributor may be the manual clean-up I did before running the cleanup tool and the new install. This was in XP SP3, and my efforts were limited to deleting the AVG and MFAData subtrees in Documents and Settings, All Users, Application Data. I did no registry cleanup (either manual or automated), nor did I clear other Documents and Settings or Program Files AVG locations (where leftovers are trivial compared to 100M or so for each of the two I deleted). I did delete \$AVG from hard drive all volumes, and both old and new AVG installations were to a non-default path in C:\Program Files.
Also, before uninstalling AVG originally, I cleared Virus Vault and logs via the AVG UI, and during the uninstall thereafter, checked Yes to clear the Virus Vault, but not User Settings. The latter are probably held in the small Application Data locations in the per-user subtrees, where I did not delete anything. I also (heh, lot’s off “also”, all of which should be declared in case the bug hinges on them) deselect the “security toolbar”, opt out of sending info to AVG, delete unwanted desktop shortcuts and relocate Start Menu shortcuts to a different folder within the same All Users, Programs.
So, steps to avoid this issue:
- shutdown and restart after running the AVG cleanup tool
- check HKLM..RunOnce is clear
- then do the fresh install of AVG
- shutdown and restart Windows
- check HKLM..RunOnce is clear
- check AVG is present and running
- re-check AVG is present and running after further startups
Some of the re-checking should be redundant, but I’m reluctant to turn my back on it again!
Perhaps the time has come to use Microsoft’s free antivirus instead. I’m less keen on Avira (the Rescue CD is prone to false-positives) or Avast, but they’ll have their proponents too. I’ve used and supported AVG for years, but am getting fed up with frequent large new versions, unwanted Do Not Track and “PC Tuneup” stuff (including the especially-unwanted “registry cleaner”) and the way recent versions push users into using these unwanted items.