Running programs between partitions / operating systems

I am running two versions of XP on separate partitions. I will store newer versions of programs on one version (XP1), and run older programs on the second (XP2).

While I am in XP2, I want to be able to access the newer programs from XP1 and vice versa.

The problem is that the registry information for any program is stored only on the OS that the program was initially installed on. So if I try to access a new program from XP2 to XP1, I always get “missing serial number” messages.

I need a way to overcome this. Either by sharing my registration info between operating systems, or by other means.

I heard VMWare might be a solution to this problem. I wouldn't need the partitions anymore... But the VMWare server is 143MB and I currently only have access to a dial-up connection. Besides, even though it allows you to run two operating systems at once on one partition, I still don’t think it would solve the registration problem between the two OSs.

Any other sugguestions?

a.