You're free to use it, it just comes with a few restrictions.
First, once you activate it, it's locked to that system's hardware configuration.
Second, there's no support for it whatsoever.
Otherwise, it's a fully functioning copy that you are free to use.
Please help. I bought a copy of the above online to overwrite my French version of XP. I see, however, that it is intended for PC server manufacturers and assemblers ONLY. Does this mean I cannot use the disk to overwrite my software? I'm reluctant to try it without advice. Unfortunately, my husband broke the seal on the package when it arrived so presumably I can't exchange it if necessary.