Sorry , just noticed this thread..Ist of all, i would go with a larger hhd. a 40gig hhd will lag in speed, depending on which one you have.
Second, I f you are "getting a error loading operating system" it can mean a number of thing's. So let's just go on down the list :
1st) of all is the drive on the end of the I.D.E cable set to master & your jumper's correct ?
2nd) is the boot order set as :
1st boot cd drive
2nd boot floppy drive
that should be the boot order set in bios, make shure the 1st thing to boot is the Cd rom drive.
3rd) make shure your CD that your installing windows from is clean from debre. smears...ect.
4th) when you make a partition, make shure it is set to active in bios.after the partition is done , then it must be formatted, usually windows will do this automatically.if not after the partition is made..
if it does'nt formatt it for you, then do it by using fdisk at the command prompt formatting
..hope that helps.