The file should be zipped or RAR'd. WHen you extract it you should have one ISO file. IF you have more than that, then the files in the ISO were extracted and that is NO GOOD. If that happened, try right clicking the ZIP file and have it extract that way.
After you have a single ISO file, you will need to burn it to a CD-R/CD-RW AS AN IMAGE FILE (Not Data) and boot from that CD (Likely you will need to change boot sequence). After boot, you should be in a DOS session. Just follow the directions and when the updae has completed, removed the CD and reboot. Check you BIOS settings to make sure that nothing got changed.
If you need the ISO file, I can e-mail it to you, PM me with your email address.