Please,try System Restore
INFO:
System Restore is a component of Windows XP that you can use to restore
your computer to a previous state, if a problem occurs, without losing your
personal data files (such as Microsoft Word documents, browsing history,
drawings, favorites, or e-mail). System Restore monitors changes to the
system and some application files, and it automatically creates easily
identified restore points. These restore points allow you to revert the
system to a previous time. They are created daily and at the time of
significant system events (such as when an application or driver is
installed).
---
Restore your computer to a state a week before the problem started.
If this doesn't help ,
check your computer for malware :
http://www.pandasoftware.com/products/activescan/com/activescan_principal.htm
Panda Software free Active Scan,where you can check your
PC for ALL TYPES of security threats and clean viruses and worms
http://housecall.trendmicro.com
Trend-Micro free online scanner HouseCall where you can scan for
Viruses and Spywares and clean them. CWShredder is also available here
http://www.kaspersky.com/virusscanner
Kaspersky free online scanner
and checker for suspicious files.If you have issues with suspicious
file,here is the right place!
http://www.microsoft.com/malwareremove
Microsoft Windows Malware Removal Tool
If this does not help,please try Repair install of your Windows XP using the
CD.
<<< Tip ! Before that create a back up of all your importatnt data >>>
If you do not know how to do full / repair install ,you can take your
computer to a PC store where IT specialists would help you wipe out those
problems.
Good luck !
Panda_man
" Let's beat malware black and blue "
" No new epidemic of all kind of malware -> Panda TruPrevent "
Certisified from Microsoft BG " Protection and Security for Windows XP with
SP 2"