It's probably because some registry settings were changed/removed during the infection/cleanup process. The malware probably changed registry keys, then when the malware was removed, the incorrect/infected keys are still there. The registry points Windows to the program to use for certain file extensions. When these are screwed up, nothing will run correctly.
You might be able to just uninstall, then reinstall all your programs (use Revo Uninstaller
). Or you might have to reinstall Windows entirely. Sometimes, malware can screw up a system so bad, that the only thing that will fix it is a clean install.
Sorry to be the bearer of bad news.
Somebody else might come along with some brighter options, but that's all I've got.
You can try to reinstall the programs, but the best option after a severe infection like this is a full format and clean install.
Edited by keyboardNinja, 01 March 2010 - 11:12 AM.