If you want to upgrade your family computers to Windows 7, it's not going to cost you an arm and a leg. Windows has released the Family Pack pricing. Officially priced at $149, it's actually a pretty good deal, compared to previous Microsoft upgrade pricing. If you are wondering whether you should upgrade or not, I recommend you do. Windows 7 is a good operating system, as evidenced by our experiences of running the Release Candidate of the software.
The Family Pack will let you install 3 copies of Windows 7 Home Premium. There is additional pricing released for individual computer upgrades as well. If you want the details, you can find it here.
To Your Success,
Tim