Wondows 98 Master Error Log

It has been some time since I had to troubleshoot a Win 98 problem, but a friend has a problem.

I know that there is an error log file for all errors that a user may get from Windows 98. I can't find it, or any information on it. Can you help? They don't remember the error, and it would be a great help just to find it in the log file.

Thanks for your help!