Sounds like you got a data miner installed.
Go to
www.cnet.com and get ad-aware, spybot and HijackThis (all free) and run them in that order. Between the help and the information on each item found (you can Google the filenames) these programs can fix you up. If there is a bug found that these programs won't kill, then google the bug. Someone will tell you how to kill it. Sometimes it is required to boot your computer in the safe mode to get the bugs removed. Safe mode is always the better mode to run these programs.