You may have multiple user accounts on your system. Try clicking "Start", then "Shutdown", and see if it will let you log-off from whatever account is active. If it does, it will look like it is shutting down, then will give you a login screen, where you could type in:

Adminstrator

Try leaving the password field blank and see if it lets you in.

From there, you could go to the control panel and click "Users and Passwords" and give your normal account Administrator rights. Then logoff as Administrator and log back in with your normal account.

I'm hoping this all works in Win98. I've been running Win2000 so long, that some of this may or may not work for 98. But, give it a try and let me know how it goes.