New life for old XP

It seems to me that it is just as easy to keep XP on an older computer if you really need it to run an old program. I have a car manual program that simply won't run on Windows 7, so I run it on a laptop that is running XP. Security is not a concern because the laptop is never connected to the internet. I simply need XP to run this older program. Why go through all the hassle of a VM?