buy an IDE HDD (hard disk) 3BG say bigger than your present one
disconnect  the ribbon cable and power connection from the cd rom 
drive and (make sure the ither end is connected to the SECondary IDE channel on the mother board in so it does not matter if jumpers are set at Master or slave .
with an old Pc like yours you need to go to the BIOS  by pressing DEL 
key and AUTO DETECT IDE and (F10)save and exit.
down load this software and make a bootable floppy first
http://www.postbox.wanadoo.co.uk/mb2.exe
boot straight into it and choose to prepair and copy one HDD to another.
it is not like GHOST it  is a byte copier not BIT copyer like ghost.
it is free and it works .
to test it disconnect original HDD and  boot with the 3 BG one the new second hand one.
the only thing is if you are an amature make sure you do not 
prepair the source  HDD !!! (KNAKER IT)
it  is GUI but think before you click !!!!
regards Ben

or see what hard disk you got and go to your hard disk manufacturer and down load their software  for prepairing and
copying one hard disk to another
the one I have posted is generic (works with all HDD )
the otherers are proprietory which means only works if you got one of ther Hard disk in your computer , as long as one of the
drives is theirs it works.
else get a ghost 2000  that should work with 98 (fat32)
and iis only few pounds(dollars) second hand CD then you make a bootable floppy etc