Most of the posts are regarding problems and user queries. Thought i will post something different.
On the office comp i am currently working at, the bundled Norton Internet Security Suite that came with the system had become ineffective as the subscription had expired. Being a govt setup, renewal would have been expected to take eons or not be available at all. As regular pendrive interaction is there, inevitably the system became infested with viruses/malware and things came to a crawl. (MBAM later on found 125 malware on it)!
Formatting would have been a tedious option. First AVG was installed, but it came a cropper. Used to go crazy, telling that every executable opening is infected, but doing nothing about it. Finally removed it too, using Revo Uninstaller. Downloaded Hijack This.. it found some entries of CA antivirus too, someone else may have tried installing it earlier. Uninstalled all doubtful startup entries using CCleaner. (All downloading was on separate computer, as no direct net connection).
Finally, downloaded latest version of Avast from net. Installed it, it took care of the viruses. And since then the system is running like a Ferrari! :-)
One glitch is that the system is not connected to the internet, so perforce the updating of the VPS will have to be infrequent. But some protection is better than none, and anything is better than having a Norton with expired subscription!