cvs commit issue on windows

I recently downloaded cvs for my windows XP machine.. It had a single
cvs.exe file in the zip.

The version is 1.11.2 (client).

When I do a commit of my changes it gives me a message:

cvs [commit aborted]: your apparent username (rajal) is unknown to this
system

How do I fix this problem.. All the files checked in so far, had the author
as "unknown".

--
Rajal