At MB Autowerks we use Service2000 from GenesisFour.
We looked at most everything out there and S2K is the best hands down.
It is based on a Progress database which is an industrial strength database...unlike wimpy Access.
It runs on Windows 2000 and has an excellent GUI interface much like Microsoft Office.
The program has lots of optional modules so you can tailor it to your specific needs.
The service & support is first rate.
I HIGHLY recommend it!
Check it out:
Service2000