Were you referring to winwasher or Webwasher? I'll have a good guess programs of this sort are spyware or comes bundled with them.
Even if you did a clean uninstall, the original installation already contains files that are left in your comp or registry files. These tracks and monitor your online activity without your consent. EVEN AFTER you have uninstalled the program.
That could possibly explain the reason why it happened. Such spyware always eat up precious disk space. To get rid of them, you have to download a program called Ad-aware that specifically detects and removes spyware.
It is very popular and is free. It clears away cookies and traces of internet activity, cleans up registry files. However, its not the most powerful one i have seen although it is good enuff.
For the best solution, check out Cyberscrub.... it deletes all deleted items that may still remain locked in your system without recovery. So even if you have deleted webwasher and cleared the recycle bin, it still remains somewhere in the comp.
