If you don't have a number on the case of the disk itself look if you can find a Certificate of AUthenticity that might have come with the computer.
On there you may see something like this 854 OEM 38569387
I made those numbers up so do even bother trying them they probably won't work.
As an alternative I can highly recommend Open Office.
It is really great if you only need a word processor, A spreadsheet program and something for presentations.
It is very intuitive so you won't need to many instructions.
go to openoffice.org where you can download it for free. No serial numbers needed. To prevent spyware in the future I recommend not using Internet Explorer. Mozilla Firefox is a much better browser and it lets much less spyware through.
www.mozilla.org
Check it out. Forget Microsoft techies. They aren't there to help, they are just there to sell.
Good luck
Afraid I'm a very non computer person. My pc hard drive had to be erased due to a virus and spyware problems. I am now installing all my software, pictures, etc. back on my pc. I have Windows 98 and I had no problem reinstalling. When I went to install my Office 97 the disk asked for a 20 digit security number. I don't have a clue, what I did with it. I called Microsoft tech. help and was told there is no help available for Office 97 only the newer editions. Do I have any other options. Thanks

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic