Does your passwork use only normal letters (a-z, A-Z) and digits (0-9)? Those should be the same on all usual keyboards. It might different if you use other characters.
With encrypted files, we recommend having an unencrypted backup, safely stored.
I encrypted my whole system using truecrypt and have entered the password for that in a pre-boot environment without any keyboard drivers loaded, that's where I enter the password every time I boot too.
My problem is, that I can't mount the drive using any other way - when I try to mount it as a encrypted system on a Linux Live CD, Truecrypt keeps telling me the password is wrong. It tried all kinds of different keyboard layouts, none worked.
This of course means, that if my PC ever breaks down and I need to get to the data using a different PC, it won't work.
Now to my question: is there any way to try out the keyboardlayout in this pre-boot, BIOS environment? So I can see which keystroke produces which letter? Is there for example a DOS or Linus Version which doesn't load it's own keyboard drivers before launching a cli?