Printers not listed in windows 98

Hi everyone,

I have come accross a strange problem. One of my client has Windows 2000 server and Windows 98 clients machines. From past 2 days i am facing a strange problem Windows 98 is not showing installed printers as well as it is not responding to word, excel, outlook etc. I have scanned all computers using pc cilins house call.
It says there is no virus. What could be the problem?????? Is there any unknown virus????

Urgent suggestions required!!!