[invalid product key on new cpu]

I've just purchased this hp and the cd that was provided to me with the
product key sticker on front does not work. I was under the impression that
there would be some type of trial period that would allow me to use the
product to determine if I want it or not. I am unable to open any documents
in word on my cpu because this software has somehow locked me out of my
papers for school. I can't edit copy or even view the docs w/o the product
key. The product key provided is 7X4P3 Q24MX KHRKH R6CX2 G76Y4 it clearly
doesn't work rather it is in lower case or upper case format. Please reply to
this posting as soon as you can. I have a paper that is due immediately!!!