Need to reinstall 98 from disk

I used the compaq restore disk and obviously did something wrong. It now only says no OS and will not do anything. HELP this is a Compaq 1200 notebook if that is any help. Was trying to restore it back because it was running poorly and was planning to upgrading to XP but don’t want to purchase it untill I know I can install it. Any help would be greatly appreciated seeing that it is not mine :(.