My previous post doesn't apply to you. I forgot, you're with Win 98.
Try this. Go Start>Run, type in:
regsvr32 wuapi.dll (<---watch for "space")
Click OK.
Repeat the very same command, substituting wuapi.dll with following files:
• wuaueng.dll
• wucltui.dll
• wups.dll
• wuweb.dll
• atl.dll
• softpub.dll
• wintrust.dll
• initpki.dll
• mssip32.dll
Note: Since you're with Win 98, some of the above files may be not present (command will create an error, but don't worry about it). In that case, proceed to next command.
Restart computer, when done.