I now have 7 on 2 of our 6 machines. It works quite well and seems faster than XP. When there is a problem, it can be set to emulate earlier versions although this has not occurred on our machines. I am rapidly becoming a fan of 7.

For you, the key is whether the RAM is large enough for 7. You need at least 1 Gig.

As the machine was running Vista, there should be no problem with an upgrade. I took this machine to 7 Ultimate from Vista. The mini came with 7 intro version on it and I have seen no reason to upgrade.

If you wish to use Internet explorer 9 you will need 7 or Vista, as there are compatibility issues with XP.

I got my copy of 7 Ultimate from Discount Mountain [advertised here] and was very happy with their service.