Available for the lightest weight OS
Available for the lightest weight OS
Xbuntu and Lubuntu are the top options that come to mind. I strongly suggest one of these if you're not very familiar with Linux, since Ubuntu is generally the most accessible Linux distribution.
Puppy dog Linux seems to require around 15 MB in storage, but I have no idea what it includes.
I had a positive outcome restoring a laptop using Lubuntu, though it wasn't very old—some Celeron models with a 468 socket and 512MB RAM, originally shipped with XP. However, if you have no option but to revert to Windows 98, I suggest opting for Windows 2000. It helped me avoid frequent reinstallations at that time (it's NT-based, unlike XP which became incompatible). Alternatively, you might consider trying XP as well.
It seems you're recalling how outdated your system was. Back then, a few hundred megabytes were enough to get things running.