That's remarkable. There are few, if any, updates for Windows 98 anymore. And did the laptop do it automatically by itself, or did you do it? What update and why?
A scanreg /restore might be a solution, of you have to apply the full power of the recommended clean boot troubleshooting procedures (three articles on the MSKB), but before doing such please tell more.
Last week my laptop with windows 98 did a update from microsoft. It stated it had to restart. Now it boots up to the password, then goes to the main screen and locks up. Nothing works. Any advice???