hi, windows 98 was deleted off my computer, kids tried loading a GAME and they ran out of disk space, they started deleting things and got to the windows program. as soon as the computer is turned on  a message comes up about MISSIN 98 files it then goes to the windows 98 setup wizard, i can get throgh te first couple of questions untill it asks for the product key. i enter it and it always comes back invalid, then suts the computer down. this is the same product key that i installed awhile back and it worked then. ive entered it a few times to make SURE i didnt get it WRONG, same results.  at staples the TOLD me to try a different 98 product key and it should work, will itLikely yes, but where do you plan on getting this key? Legally, I presume . Anyways, do you have your disk? You could always make fresh start and completely reformat and reinstall; may fix some other problems you don't know about and free disk space.
Let us know how it turns out, good luck!

/me wishes there was link in post page to add common phrase lik ^ to any post