It is not easy to move a software program from one computer to another.
When you install any softwae program it not only puts the files on the computer but also updates various Windows system files such as the registry.
Finding out what it puts in the registry and other system files is very difficult.
The only real solution is to install the software from scratch on the new PC (although my guess is that you have not got the software to install).
Note also that you may need a special version of Picture it to run under Vista. Not all software written for XP will run inder Vista.