|DAVEINCAPS: I don't know how they'd differentiate between corporate and regular users anyway.|
Normally you give them your support contract number when you open a support request.
Anyways, mainstream support ended a few years ago. Microsoft said they'd release security fixes until the end of extended support, 4/8/2014. WinXP is considered a business product, so mainstream support lasted for 10 years after release, and extended for 5 years after mainstream.
How To Ask Questions The Smart Way