yes you can.
attach your new drive to the middle of the 'primary' ide cable your other hard drive is already attached to and set its jumpers to 'cable select' or 'slave'
set your current hard drive to 'cable select' or 'master' either one should already have been set.
if both are set to 'cable select' then depending on which end of the ide cable they are attached to they will assign thier correct rolls as master or slave. the one on the end of the ide cable is master, middle connector (half way along ide cable) is slave just check the jumpers.
when you attach it then boot into windows, im guessing you have xp here then click 'start/control panel/administrative tools/computer management/disc management' then right click your new disk and select 'format'