have you tried formatting the drive? check the cables just to be sure...and the jumpers too...is it on the same IDE cable as the master HDD or the CD-Drive? check to see if the HDD is on slave or master if its on a different IDE cable...could be a number of things...
you say you cand access it, i think you will need to fdisk it to prepare it for writing to
first of all, is it visible in My Computer, if it is then right click it and choose format. use full format for the first time, takes longer but not too much
if you cant see it in My Computer then use a windows98 floppy disk, reboot your pc with the floppy disk in and when you get the menu, press shift+F5 (i think its shift, look at the bottom of the menu page and press whatever it says for command prompt only)
once there type fdisk
i think its option5, change fixed drive, choose the slave drive (probably drive2) drive1 should be the first drive. MAKE SURE IT HAS CHANGED BECAUSE AT THIS STAGE YOU COULD WIPE YOUR MAIN DRIVE YOU HAVE BEEN WARNED
then from the menu (you may have to press ESC to get back to the menu) choose option 1
let it use the full disk space or split it however you wish.
once you have set up the drive/partitions, escape out of fdisk, remove the floppy disk and reboot
once rebooted your new drive should be visible in My Computer but you will still need to format the drive/partitions as described earlier.