Help identifying, removing virus

[858diver]

While updating Win98SE to install the latest security patch on a computer used as a print server on our home business network, it seems that the computer has a virus, as the patch could not be installed, the keyboard has been disabled (under windows only), and VirusScan will no longer load. I attempted to run VirusScan under DOS mode, following the instructions found in Mcafee Document 401 - here:
http://ts.mcafeehelp.com/faq3.asp?docid=401. The scan can be initiated, but stops after the following message appears on the screen:
Checking memory for viruses...is ok.
The good news is that the printer can still be shared by other computers on the network, and shared folders can also be accessed, so worst case, I could simply reinstall the OS.
Can anyone offer any words of wisdom to prevent such drastic actions?

Update: Was able to run the browser-based free virus scan from Symantec, which could not find any viruses. Also read spyware threads, ran both Spybot and Ad-aware and deleted / disabled several items, but still no luck. One other symptom - computer will not double-click launch any items - requires a right click / open.

 

[858diver]

Added additional info - but still no luck - anyone?

 

[John]

I also recommend and use the Panda Online Virus Scanner http://www.pandasoftware.com/activescan/ plus the Trend Micro Online Virus Scan http://housecall.trendmicro.com/housecall/start_corp.asp

 

[FreakyGuy]

If it's not a virus or spyware, how much hard drive space is left on your computer? How old is your computer and do you think something could be failing? CPU fan, Hard Drive, PSU etc... When was the last time you cleaned up and defragged your hard drive?

Just some suggestions for troubleshooting.

 

[858diver]

Thanks for the feedback.

Due to the inoperable keyboard, web-based services that ask for sign-in information are very difficult. With some effort, I was able to run the Panda version. Toward the end of the scanning process, a dialog box opened, asking for the location of what appeared to be an Outlook pst file - in.pst, which should have been located in a system\common\mapi file folder, 1033\95. After the scan, I accessed the folder, and could not find any .pst files. As it has been more than two years since Outlook was used on this computer, I do not recall if the .pst files should still be there.

The machine is going on 5 years old, and the hard drive was harvested from an older machine. I run defrag and scans on a weekly basis, and everything seems to check out fine. As mentioned, the primary function of the machine is to share a connected Xerox laser printer / copier, that does not interface with a printer server (any I could identify).

My primary concern was that the virus (or whatever has caused the malfunction) prevents Virus Scan from loading, so the computer was completely unprotected. For this reason, I uninstalled Mcafee and installed AVG 6.0. The good news is that everything seems to be functioning properly now!!!

It would be nice to know the case, so any other comments or suggestions are welcome, but everything again appears to be in order. One possible casualty: The menu options of the start \ shut down button no longer function. Any suggestions as to what function I may have disabled to cause this?

Thanks again!