[Virus] AU lancement d4internet Explorer

Bonjour a tous, j'ai un petit soucis lorsque je lance Internet Explorer, au lieu de m'affiche ma page d'acceuil habituelle, le site (hhtp://iehomepages.com.com/) s'ouvre, avec un message disant :

Warning!

W32.Pysor.FK@yf is a virus that infects files with .exe extensions. It attempts to steal passwords and privates information from the infected computer.

Type: Virus
Infection Length : 138,293 bytes
Systems Affected: Windows 95, 98, ME, NT (all versions), 2003, Windows Xp (all service packs)
Systems Not Affected: DOS, EPOC, Linux, Macintosh, Novell Netware, OS/2, UNIX
Technical details : 1. Creates files in %Windir%\ directory. By default, this is c:\Windows.
2. Adds values to registry keys: HKEY_LOCAL_MNACHINE\Software\Microsoft\Windows\CurrentVersion\Run
3. Scans the hard drive for .exe files and infects any executable files.
Searches for passwords/information, whiwh it may send to a remote attacker.
Recomendations : Clik "OK" to download officially approved security software. Always keep your patch levels up-to-date.

Case "OK" - Case "Annuler"

Merci de bien vouloir m'aider, et me dire ce que je doit faire.

Config:
Windows XP familiale. 1,6Ghz . 512 Mo RAM