What you want is not some hacky per-program patch or hacked up MSIs.
What you want is the Microsoft Application Verifier
This program will make ANY program think it's on XP or any other Windows OS.
Usage:
Download and install first.
Launch it, deselect the Basics, select HighVersionLie.
Right click and open properties.
Now, key in these settings (which work for me, not sure about service pack stuff, someone want to enlighten me on that?)
The settings, repeated in text:
5, 1, 2600, 2, 2
As a last, optional step, click on the excutable-name and set Propagate to TRUE. This means that child processes will also be lied to.
Now click save and install the app, you need to experiment with exactly which executables you apply to, some need msiexec patched, others (Like CS3) just need setup.exe.
NOTE: If you hook msiexec, you need to kill the process before it will work.
Don't forget to remove it later, as this is a system-wide setting.
As for other uses, not sure if this could make some XP only apps run on 2000, I'll leave that up to you for testing.
Here's a screenshot proving this works:
