NIS Subcription Question about Windows 7 Professional and XP Mode

I have a NIS 2010 subscription for 3 PC's which I have installed on 2 laptops and a desktop.  The desktop has Windows 7 Professional 64 bit.  I also installed XP Mode on this desktop to run programs I have that won't run on 7 and was doing some research and found out that XP Mode should have it own antivirus installed.  My question is; With my 3 PC installs used on this subscription, can I install NIS2010 on XP Mode seeing that it is on the same Desktop PC with Windows 7 installed?  If so, is there anything special I have to do to install it?  My reasoning says yes I could because is it is the same PC that needs the protection and not an additional PC but I don't know for certain and would like someone that knows for sure.  Can someone help?  I hope I am in the right forum for this question.