|Do you know if it's a HDD password or bios password? I'm not sure if one that old had the ability to set a HDD password. This is a link to the manual:|
It should give some info on that:
My guess though is you're out of luck on breaking that password. You can try contacting gateway but they probably only have fee-based support, if they have any support at all, for something that old.
If it's a HDD password you may be able to replace the drive and reinstall 98, although sometimes HDD passwords are linked to the bios so any new drive has the same password.
It's a pentium 3 so it's not worth putting a lot of money into it. If you're looking to recover some of the files you may be able to remove the hard drive and attach it to a USB enclosure or adapter and view its contents on another computer.