Cheval de troie

Bonjour.
Sur mon ordi j'ai cela:

TrojanSpy/Win32.Agent.L
Trojan:Win32/Dialer.CScan started at 20/07/2004 23:29:41

Scanning memory...
Scanning boot sectors...
Scanning files...
C:\Documents and Settings\Propriétaire\Local Settings\Temp\_update.dat - TrojanSpy/Win32.Agent.L -> Infected
C:\WINDOWS\Downloaded Program Files\Dialerdata.dll - Trojan:Win32/Dialer.C -> Infected

Scanned
============================
Objects: 47914
Directories: 3053
Archives: 17391
Size(Kb): 2009847
Infected files: 2

Found
============================
Viruses found: 2
Suspicious files: 0
Disinfected files: 0
Mail files: 103

merci de votre aide...