WD External HD not backing up thru Time Machine and can't access files

Question

Hello,
This is the snapshot picture of my problem:
http://i668.photobucket.com/albums/vv43/no-real/computer/Picture1.png
When I connect the WD 500GB drive to my Macbook Pro, the computer doesn't recognize it in the devices list (The WD-HD seems running when I connect though USB or Firewire), nor the Time Machine can find it.
I'm hoping someone can help me after exhausting all resources I checked on the net.
This problem suddenly started about two months ago, whereas before there was no problem for about two years.
I read forums and one said to start Disk Utility and have it recognize the HD. The first time it didn't recognize it, but starting and quitting Disk Utility few times the HD was finally recognized. However, the Verify disk or Repair disk can't be completed (Error sign) The snapshot of my situation is like this:
http://i668.photobucket.com/albums/vv43/no-real/computer/Picture1.png
Another forum said if the HD was formatted for Windows (Which I used for the first few months using this WD-HD) and wasn't formatted for Mac, which I can't remember if I did, this could be causing problems?
I'm very careful about ejecting or shutting down my External HD properly, and I can't remember a time when I disconnected it improperly (Who knows, maybe I have)
Any thoughts and/or solution for this problem? Or am I doomed to reformat the whole drive.
The iomega Drive you see in the snapshot is a new one I bought and works just fine.
Thanks

Answer 1

no-real wrote:
So I tried everything but to no avail.... I will reformat the disk. Luckily I had most of my critical files on the Mac HD so... the damage is not all that bad!
Thanks for all the help here... and when I went to the apple store today and consulted, they said it is a better idea to store on two separate disks, one with time machine, and one with the old fashion drag and drop to diversify risk.
I'd disagree with the second part of that -- drag and drop is not a good backup solution. I've learned over the years (mostly the hard way, of course ), never to trust my backups to a single app or piece of hardware: no app is perfect, and all hardware fails, sooner or later.
Like many here, I keep both full Time Machine backups, plus a "bootable clone" on a separate external HD. I use CarbonCopyCloner, many use the similar SuperDuper. That gives me the best of both types of backups, plus of course a completely separate, independent backup.
CCC is donationware; SD has a free version, but you need the paid one (about $30) to do updates instead of full replacements, or scheduling. Either is easily found via Google.
And/or, see Kappy's post on Basic Backup, complete with links to the web sites of each product.
And by chance, before I will reformat, is there a way to access this External disk with some files? It shows up on disk utility.... maybe a way to just manually pull out some files?
Since it doesn't appear in the Finder, no.