My old Dell Axim X51 PDA

I still use and rely on my old PDA as my extra brain.... I don't loose it, I do loose my phones so do not want to keep anything important (such as passwords, etc) on my phone. 

I recently thought I should probably take a copy of the info on my PDA and store elsewhere so that I could access from my computer should my Axim die.  Come to find out, I'm unable to open the .dbk backup files on my computer.  Suggestions anyone?? 

I have so much info on this thing and it's starting to act up a bit.  I can't afford to loose all this info.  (I have a 2+ year old XPS running Windows 7 Professional)

Thanks!