There is a very good chance that you are seeing the effects of a
hijackware infection!
NB: If you had no anti-virus application installed or the subscription had
expired *when the machine first got infected* and/or your subscription has
since expired and/or the machine's not been kept fully-patched at Windows
Update, don't waste your time with any of the below: Format & reinstall
Windows. A Repair Install will NOT help!
1. See if you can download/run the MSRT manually:
http://www.microsoft.com/security/malwareremove/default.mspx
NB: Run the FULL scan, not the QUICK scan! You may need to download the
MSRT on a non-infected machine, then transfer MRT.EXE to the infected
machine and rename it to SCAN.EXE before running it.
2. [WinXP ONLY!! =>] Run the Windows Live Safety Center's 'Protection'
scan (only!) in Safe Mode with Networking, if need be:
http://onecare.live.com/site/en-us/center/howsafe.htm
3. Run a /thorough/ check for hijackware, including posting the requested
logs in an appropriate forum, not here.
Checking for/Help with Hijackware
http://aumha.net/viewtopic.php?f=30&t=4075
http://mvps.org/winhelp2002/unwanted.htm
http://inetexplorer.mvps.org/data/prevention.htm
http://inetexplorer.mvps.org/tshoot.html
http://www.mvps.org/sramesh2k/Malware_Defence.htm
http://www.elephantboycomputers.com/page2.html#Removing_Malware
**Seek expert assistance in
http://spywarehammer.com/simplemachinesforum/index.php?board=10.0,
http://forums.spybot.info/forumdisplay.php?f=22,
http://www.dslreports.com/forum/cleanup,
http://aumha.net/viewforum.php?f=30 or other appropriate forums.**
If these procedures look too complex - and there is no shame in admitting
this isn't your cup of tea - take the machine to a local, reputable and
independent (i.e., not BigBoxStoreUSA) computer repair shop.