a better suggestion is, restart in ms-dos mode
type format c: then y to accept, have a cd ready
if you must a win98 disk, but prefably a xp or
linux disk, and redo your whole system, and then take
care of it from there,
before you actualyl do any of this realize all data will be lost
so back up anything important.
also dont do this if you dont have a bootable operating system
also if this is not a option, if you are out of space and
are just tired of the warning that pops up there a way to
disable it, im not sure what the command is for win98
but i know one exsist, so just lookt hat up on google.
if you actually consider formating, and need additional advice or
help feel free to msg me on a instant messenger from my profile
or pm me.