I am currently running windows xp pro, which I bought OEM from Newegg.com. This is a legitimate/legal copy, which is tied to the crappy system I'm using right now.

When I purchase my new uber system, what will happen when I install windows xp and use this same cd-key? Will validation/activation be denied? Will a simple call to Microsoft fix this?

Thanks much.

What are you going to do with the old computer? If you're going to decommission it, you can use the same copy of Windows and tell MS your motherboard died. If not, you need a second copy.

Grumpy

Ya my old mobo and such will be just sitting in my closet. Will I have 30 days or so to activate windows xp? hence 30 days to call them? without xp being crippled

You have the 30 day activation, same as the original installation. I've had numerous mobo failures

Will validation/activation be denied?
not unless you've activated your other copy more than twice already


Will a simple call to Microsoft fix this?
yes, just tell them its only installed on one computer but your hard drive crashed or something then you can activate it and use it on both =)