I have upgraded to Snow Leopard and Lion on my two MacBook Pros. I just found out that both do not work with Parallels 3. I just do not want to spend 79.00 dollars to buy a new version. Can I just upgrade or run an update?
Nope. You can only upgrade to 7 from 5 or 6 (and upgrade to 6 from 5 and 4, but 6 is no longer available for sale, anyway, 3 is out of the scope).