Originally Posted by Laptop_Matt
Yes as long as the Sticker matches the CD ie XP Home or Professional.
That's not actually true.
There are 4 different media types available direct from Microsoft and you cannot use a activation key from another type with the different media sets.
MSDN - Developer Releases
OEM - System Builder
RETAIL - Off the shelf
VLS - Volume Licence Subscription
Some OEMs use various tools to create their own discs so these again will also have different criteria, the discs keithyboy may be talking about could be recovery discs not installation discs, or could be OEM discs which will work with his OEM licence Keys.
One thing to remember for Keithyboys knowledge. OEM licence keys can only be used on the machine they were originally installed on. It's a limitation of a having a nice cheap licence.
If you purchase a new 'to you' machine and decide you want to port your copy of windows across that would be illegal.
This may not worry you now, but a likely scenario could be that if at some point in the future you were looking to get a new computer and thought virtualising the existing one in it's current state would be useful in case of compatibility issues then you would not be able to do that, OEM windows detects the hardware change and will not allow you to logon.