My Passport - restore to original factory condition?

Good morning.  I have a Western Digital Drive (WDME2500TN).  The drive was recently formatted, and I am looking to put the original software back on it, so that I can password protect the hard drive.  I have been looking at this for a few days now, and from what I can gather, this model of hard drive is not recognized/not seen with WD Smartware.  I have installed SES drivers, installed WD Smartware, but when SmartWare is up, it does not recognize the drive.

However, windows has no problem seeing the drive, as I have formatted it numoerous times, copied data on to it, etc. 

When I bough this drive about 3.5 years ago, it came with some WD software on it, that let you put a password on the drive, etc.  How do i get this software back?  I have read the online pdf manual, and it tells you to search in the KB for a number, which points you to a page to download software.  However, the “original factory software” is not available on the WD site.

Can someone please tell me

a) where to find the original software

b) how to get smartware to recognize the drive, so I can put a password on it.

My end goal here is to password protect this drive.  Please help!

This drive is not Smartware compatible, this is the old version of the WD Passport.

You can find the software for this drive in the link below:

Thanks for the reply.  What software do i need to download from that link? (i.e. - what software will allow you to password protect the drive)