Without CD's, do not attempt this. Or use the CD from your husband's computer, if they're both the same version of Win98. There's Win98, Win98SE (Second Edition), and sometimes a special Win98 for the paticular computer.
Try and clean the spyware any way you can and avoid formatting. Once you format and try to reinstall, you will need all the drivers for the internal devices (modem, video card, etc.).
A reinstall without formatting will not overwrite anything except the Windows files, all applications and data will still be there.