Last night I attempted to install a copy of XP SP2 from a copy of a Volume License install CD (my employer is a MS partner). During the Windows install I get a "invalid function" error - so I am wondering if anyone has had success installing from a Volume License disc? I am going to try the original CD next week, so hopefully its just an issue with the burned copy. Thanks for your response. Also, somehow the Windows installer knows what you are trying to install and won't accept legit keys from another type (Retail vs. OEM vs. Volume). Is there a way around this? *I'm not pirating here, just trying to avoid another trip to the office* I tried an OEM XP Pro CD, but it wouldn't accept my Volume License key - seems I can only use the Volume License install CD.