XP Pro install problem

I have a 1.5 year old Macbook, currently running Tiger. The version of Paralells I have is whatever was on the street at Christmas of 06.
My (unsympathetic to Mac's) IT guy at work made a Windows XP Pro install disc, with the corporate Multi user serial key, so all is legal and legit, but I keep getting a message while installing saying "serial # is not the one that came with the disc, etc".....

Is this a Paralells issue or a Microsoft problem? There is no further help with my IT person at the office........

thank you for your time and help

Chris

 

Hope you resolved, based on PM