Safe mode won't help if he has one of the types of viruses that turns off virus scanners. Some of them attach to the MBR (master boot record).
Examples of what I am talking about
:
Ex 1:
http://www.symantec.com/avcenter/ven.../mailissa.html
<snip>
Similar to W97M.Pri, the virus turns off the security protection upon opening an infected document in MS Word 2000.
</snip>
Ex 2:
http://www.viruslibrary.com/virusinfo/Implantfamily.htm
<snip>
....very dangerous memory resident polymorphic and stealth multipartite viruses. They affect .COM, .EXE and .SYS files as well as MBR of the hard drive and boot sector of floppy disks.
When an infected file is executed, the virus writes itself to the MBR of the hard drive and returns control to the host program. While loading from infected disk the virus hooks INT 12h, 13h, 1Ch, ......
</snip>
Ex 3:
http://www.norman.com/virus_info/w32_klez_g_mm.shtml
It will add an entry in the Registry so that it is loaded from startup.
This thread will go through running processes and look whether they contain certain words (Ref WL01) within the first 512k of the process' own memory space. If any of these words are found, the process will be attempted killed, and the accompanying program file will be deleted (provided it does not reside in the dllcache directory).
Note that the fact that the word list contains virus names will not always affect the viruses in question since some of them do not contain their own name - but it will certainly affect antivirus programs and fixup tools.
The registry keys HLKM\Software\Microsoft\Windows\CurrentVersion\Run and
HLKM\Software\Microsoft\Windows\CurrentVersion\Run Services are checked for the precence of antivirus programs in the WL02 list. If so, they are removed from registry.
On Win9x/ME this thread also continuously refreshes the worm's own Run key in the Registry.
!!!!!!!!!!!!! Those were just a few quick example types.
What you can do (places to start, be sure to keep the link all together):
http://www.google.com/search?hl=en&l...=Google+Search
Or just manually download patch/fixes from your virus software website. Don't rely on 'autoupdates', currently your virus software could be compromised. This could be a much longer post, instead I suggest you inform yourself with google, and then get fix(es) from sites you trust.
Oh, and really think about where the virus came from. (some exe, or an Office 95/97/2000/2002 document, Outlook/Express email...)