Try this first - AVG8.x (or higher) Remover, download tool from here, http://www.avg.com/download-tools there is a 32bit and 64 bit windows version, ensure you use the correct one.
Then try a repair of avast. Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button and scroll down to Repair, click next and follow. This has in the past resolved this out of sync issue between reported and actual VPS version.
If the problem still exists then you may not be completely clear of the infection, see #### below.
avast! icon missing - As a temporary measure until this is resolved you can create a desktop shortcut for this file C:\Program Files\Alwil Software\Avast4\ashDisp.exe (the avast icon and interface to the providers). Right click on the file and select Send To, Desktop (create shortcut). You will need to run this after each boot until the problem is resolved.
What other security based software do you have that might block new startup entries, e.g. Spybot S&D (TeaTimer), AdAware (AdWatch), SpySweeper, Spyware Doctor (StartUpGuard or OnGuard), PrevX, WinPatrol, ProcessGuard, etc. ?
Check the option in the Appearance tab of Program Settings. Or Make a link to ashdisp.exe in your startup folder. I wouldn’t try this as a first option (but a final one) as you won’t be able to find the true cause of the problem.
If you haven’t already got this software (freeware), download, install, update and run it and report the findings (it should product a log file).
Don’t worry about reported tracking cookies they are a minor issue and not one of security, allow SAS to deal with them though. - See http://en.wikipedia.org/wiki/HTTP_cookie.