Ok, todo va mejorando. El Ewido no lo pude ejecutar y el resultado de Kaspersky es el siguiente:

KASPERSKY ONLINE SCANNER REPORT
Saturday, July 29, 2006 7:00:48 PM
Operating System: Microsoft Windows XP Professional, Service Pack 1 (Build 2600)
Kaspersky Online Scanner version: 5.0.83.0
Kaspersky Anti-Virus database last update: 29/07/2006
Kaspersky Anti-Virus database records: 198178
Scan Settings
Scan using the following antivirus database standard
Scan Archives true
Scan Mail Bases true
Scan Target Critical Areas
C:\WINNT
C:\DOCUME~1\FAMILI~1\CONFIG~1\Temp\
Scan Statistics
Total number of scanned objects 10152
Number of viruses found 1
Number of infected objects 1 / 0
Number of suspicious objects 0
Duration of the scan process 00:08:34

Infected Object Name Virus Name Last Action
C:\WINNT\Debug\oakley.log Object is locked skipped
C:\WINNT\Debug\PASSWD.LOG Object is locked skipped
C:\WINNT\SCHEDLGU.TXT Object is locked skipped
C:\WINNT\system32\config\AppEvent.Evt Object is locked skipped
C:\WINNT\system32\config\default Object is locked skipped
C:\WINNT\system32\config\default.LOG Object is locked skipped
C:\WINNT\system32\config\SAM Object is locked skipped
C:\WINNT\system32\config\SAM.LOG Object is locked skipped
C:\WINNT\system32\config\SecEvent.Evt Object is locked skipped
C:\WINNT\system32\config\SECURITY Object is locked skipped
C:\WINNT\system32\config\SECURITY.LOG Object is locked skipped
C:\WINNT\system32\config\software Object is locked skipped
C:\WINNT\system32\config\software.LOG Object is locked skipped
C:\WINNT\system32\config\SysEvent.Evt Object is locked skipped
C:\WINNT\system32\config\system Object is locked skipped
C:\WINNT\system32\config\system.LOG Object is locked skipped
C:\WINNT\system32\h323log.txt Object is locked skipped
C:\WINNT\system32\wbem\Repository\FS\INDEX.BTR Object is locked skipped
C:\WINNT\system32\wbem\Repository\FS\OBJECTS.DATA Object is locked skipped
C:\WINNT\system32\WindowNewsUpdater14.exe Infected: Backdoor.Win32.Rbot.gen skipped
C:\WINNT\Temp\tmp00001bb5\tmp00000000 Object is locked skipped
C:\DOCUME~1\FAMILI~1\CONFIG~1\Temp\Perflib_Perfdat a_428.dat Object is locked skipped
Scan process completed.

Ademas siguen apareciendo mensajes que dicen algo asi: "STOP, Windows requires immediate attention".

Espero su respuesta, muchas gracias