Is there a straightforward way to return the total space USED on a drive?

We are evaluating newer backup solutions, and I want to hack together a script to go to a group of NT/2K servers (about 100) and calculate the total space used on all local hard drives. I could do some ugly stuff with CMD Dir, but it would be painfully slow and, well... ugly.

These systems may not all have WMI installed. I searched on "drive space", but couldn't find anything directly relevant.

Any ideas?

Thanks!

NMM