Pros: Windows 7 is a great operating system and the Key will work on either the 32-bit or 64-bit version.
Cons: Upgrading your motherboard. If after you load Windows 7 on your system and later decide to upgrade your motherboard and reinstall Windows 7 on the new system, you will be out of luck. All OEM Versions of the Windows 7 operating system locks to your motherboard you initially installed it on. You can upgrade all other hardware on your system except the motherboard. This limitation only applies to the OEM version and not the Retail version. So make sure you only use the OEM version of Windows 7 on a system you do not plan on upgrading the motherboard on.
Other Thoughts: Before you decide to install Windows 7 on your system, make sure your systems meets the minimum requirements for Windows 7. Don't run Windows 7 on a system with only 1Gb of memory or your system will be slow after you load your other programs on it.
I know a lot of people want the fully loaded Windows 7 Operating System they can get so they chose the Ultimate version. Don't do this, very few people need the extras that the Ultimate version has, most people only really need the Home premium or Pro versions. If you know what you are doing, these two versions will cost you less than $30 for a fully licensed and fully Genuine and Authentic OEM COA
.