Time Capsule on an external hard drive and password reset

Folks, I have a problem, and am hoping someone samrter (yes, intentional spelling mistake) than me can help. I've used an external USB drive as my time capsule, which has worked for me without a hitch for a couple of years.

I've just recently upgraded my MBP to Mountain Lion, and had noticed that everything was VERY slow. So, as a result I decided to reinstall ML by wiping my MBP hard drive clean, and doing a fresh install, which resulted in a very responsive OS.

Now the problem: when I went to restore my MacBook Pro from my TC on my USB drive, I was prompted for a password, which I provided, and have met with no success, then I ended up trying EVERY password that I could think of, and NONE of them worked! So, my question is this: Is there a way to retrieve/reset the password on my external USB Time Capsule?

Thanks in advance for any bit of wisdom

Mike.