restoring files from tape backup of old server?

Hi, all. I'm trying to move files from a Win2K server to a Win2K3 server. Both of these server have separate copies of Backup Exec on them (versions 9 and 12.5). When I try to do a redirected Restore to the 2003 server using a tape backup of files on the old server, I get an error saying that I need the Agent installed somewhere. Why can't BE ver12.5 on my newer server restore files from a tape used on the old server?? (Or how do I do it?) What if the old server had died and I needed to get the files off the tape backup? Seems crazy! Do I have to install a copy of the old version of BE to the new server??

Thanks for any assistance!