[CentOS] MD5 checker for Win2000 for ISOs

For a change, I am going to try and check the checksum before burning 
the CDs....

My burner is on a Win2000 box, and I have all 6 of the Centos 5 ISO 
images there already.

So I grab a checker from:  http://www.diamondcs.com.au/freeutilities/md5.php

And checking the ISO image files with this program, I get different 
numbers than in the MD5 hash txt file.

Can anyone point me to a 'proper' checker?