jdchevyman - is your operating system (2k/XP?) currently installed on the ntfs partition on the 80GB drive?
If the 2 partitions are different filestore types, you'll need to convert the second to ntfs first (PM can do this also) before merging them with PM.
Note: Merging partitions where one is the boot partition can be a risky business in terms of booting after the merge (you can lose the boot sector). You can create a boot floppy - copy ntldr, ntdetect.com & boot.ini from the root of the ntfs partition to newly formatted floppy. This will boot 2k/XP if the boot sector gets corrupted.
Also, if you're having a 200GB additional drive, why do you need to merge the partitions on the 80? (Assuming the ntfs partition is reasonable size)