I have an internal 80 GB WD HD that I'm connecting to my WinXP computer using an external USB connection. Windows picks up the drive and creates a drive letter. When I try to go into the drive, I get - "J:\ is not accessible. The file or directory is corrupted and unreadable".

When I try to do a "chkdsk /f j:", I get - "The type of the file system is NTFS. Unable to determine volume version and state. CHKDSK aborted."

When I try TESTDISK, it brings up this info...
* FAT16 >32M 0 1 1 3 254 63 64197 [DellUtility]
P HPFS - NTFS 4 0 1 9267 254 63 148826160
P FAT32 LBA 9268 0 1 9724 254 63 7341705 [DellRestore]

The HPFS - NTFS is what I'm trying to get to. If I try to view the files, TESTDISK tells me this - "Can't open filesystem. Filesystem seems damaged."

Any ideas? Thanks in advance for the help!

Your files will probally be recovered using a utility such as http://www.r-tt.com/ .
but befor you begin it is strongly advised that you use an imaging product (that knows how to handle error sectors) to copy the drive to a working drive. If the cause is failing sectors, heads, etc. you may be on borrowed time. If the host drive fails you will need pro help.