A virus scan shows that I have the Win32:Afcore virus in file c:\windows\system32:nxvfski.dll, I have run both Adaware and Spybot software and still unable to delete or repair this file.

Its probably not letting to delete since when your trying it its already running. I would end the process via crtl+alt+del and task manager and processes and then scan and remove.

Windows is so horrible...Use Freebsd www.freebsd.org or even linux distro.

1. Here are the manual removal instructions for Afcore Backdoor Trojan.

http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=BKDR_AFCORE.D

2. Disable System Restore, and you may want to update NAV and scan in Safe Mode and clear the IE Temporary Folder as instructed by Symantec.

http://securityresponse.symantec.com/avcenter/venc/data/download.trojan.html

3. Once the trojan is removed and all programs running, do the usual clean and maintenance routine, scan and defrag your hard drive, and create a full backup.

4. Install Windows security updates from Microsoft

Have Fun!