END USER PROOF OF LICENSE. If you acquired the SOFTWARE on a device, or on a compact disc or other media, a genuine Microsoft "Proof of License" COA label with a genuine copy of the SOFTWARE identifies a licensed copy of the SOFTWARE. To be valid, the label must be affixed to the COMPUTER, or appear on the SOFTWARE packaging. If you receive the label separately, it is invalid. You should keep the label on the COMPUTER or packaging to prove that you are licensed to use the SOFTWARE.

Q: There are cheap copies of Windows 7 Ultimate on eBay. They all claim they're legit and 100% from Microsoft. Can I trust such offers?

A: Beware of low pricing. These keys could be part of a MSDN subscription and as such may not be redistributed. If this is the case, they are guaranteed to land on Microsoft's black list sooner or later if the reseller decided to sell one product key several times. While activation may work for days, weeks or even months, your Windows 7 copy may end up being marked as "non-genuine" once Microsoft used its Windows Update service to determine the activation status. My advice: get Windows 7 from an authorized Microsoft reseller or from Microsoft directly.

Q: I own a small company with 20 PCs and would like to save some cash on Windows licenses. Should I even start looking at "Volume Licensing"?

A: You can qualify for Volume Licensing if you've got more than 5 PCs in your company. But be careful: all Volume Licenses are only eligible for upgrades. You need to purchase a full Windows license and then upgrade using the VL versions. Also, once you've assigned a license to one PC, you can't transfer this to another PC.