Usually what happens is after a free download, people install loads of malware with the main program they wanted. Look at what has been installed lately. If you see loads of rubbish, download revo uninstaller pro(free for 30 days) and remove and what is not good. When you remove programs with it, it's good to either disconnect the internet so that they can't download other programs whilst uninstalling or click to uninstall and cancel the uninstall. you will have another windows that allows you the scan the PC for left over files. you can just remove all files without uninstalling which is quicker.
That is if it's due to malware being installed but I must say that every week I see this because people don't look at what they install and just click next.
Also if it is malware, if you use google chrome, it usually get load of stuff in it main foler so uninstall it and delete it,s folder ( appdata\ local\google\chrome)
he was after some avi converter and now his pc wont connect to the internet. Tried the old "f8" into safemode but doesn't work. Any ideas? thanks
With that level of infection, I'd either disconnect that drive, connect it as a secondary in another PC, and do multiple scans with various tools.
or
Wipe and reinstall the whole thing. This will probably be faster.