Should be no problem. However, in DB2 for Windows, I believe that you need to copy the entire backup directory structure over to the new machine, and not just the backup file.
The database needs to be formatted from the 7.1 format into the revised 7.2 format, but I believe that DB2 does it automatically upon restore. At least I know that DB2 automatically converts DB2 version 7 to version 8 upon restore. I would make sure you have the latest 7.2 fixpak installed on the new machine.