Compaq presario laptop

on the above laptop it was reset to the manufactors origanial settings now the problem is I recieve this laptop from brother -in law with out the windows 98 software which the system states I need a key code from. I have a regular pc in my home as well and I can not use the key code from that I have tried. so is there any help or another code,I can put in the system so i can start to use it once again. also I talked with brother -in law and he can’t find info so what is a girl to do? thanks for any and all help you can give. sue