I had a very difficult time getting the Astra 2200U scanner to work on Windows 2000. I downloaded VistaScan 3.55 from the UMAX UK site but my computer kept crashing when plug and play tried to load the drivers. UMAX customer support send me the PV8630.sys and 1220u.inf drivers.
Copy PV8630.sys to C \WINNT\SYSTEM and C \WINNT\SYSTEM32, and 1220u.inf
to C \WINNT\INF (might be hidden, make sure you're viewing all files).
Then go back to Device Manager, remove the offending scanner and reboot.