Avast after installation disappear

[Lisandro]

I've asked because the inherit of the access rights done by Windows XP.
If C:\Program Files\ is %Program files% folder, everything will be ok. But if you install to a folder out of that %Program files% branch, well, there is a possibility of messing the access rights to the folder, at least in theory. Then, strange things could happen on installation...

[crusoe]

I have the same problem as Tafkas and Daking (disappearing avast, spybot, zonealarm)... I'd really love to know if you got to the bottom of it.

I'm going to start a new thread (hope that's the right thing to do).

[sergofun]

crusoe, please, read posts of users leni and XerraX in topic Missing avast exe file. May be it will be helpfull for you.

[galooma]

in the case of the last post it appears the rustock rootkit is a real possibility so maybe you guys should consider excluding that as well.  
online scan at F secure detects it
http://support.f-secure.com/enu/home/ols.shtml

 also spysweeper. http://www.download.com/Webroot-Spy-Sweeper/3000-8022_4-10301356.html