If you mean buying a 2010 Product Key Card, you can technically do that and download the 2010 image and activate it (it would not work on 2007) but for that to be legal licensing-wise, the activation must be done within 60 days of buying the pc. If it's an older PC, i would suggest buying a full retail package of Office 2010 H&B. It's not very expensive and gives you the right to install it on 3 PCs in your house.