How to fix Event Log is Full Error?

I got this error while working on my Windows XP computer.
For all I know, Windows XP automatically overwrites events that are less than 7 days old from the event log.
So I really don’t know why I am receiving this error.
I don’t know how to fix this, so if anyone here who can help me out, any suggestions will be appreciated.
I am running Windows XP Professional 32-Bit.
Thanks.
