This may be a very simplistic approach to the problem, but sometimes the simplest answer can save you 100's. Have you tried reinstalling the drivers/software that came with your usb stick? If it is saying new hardware it isnt reading the drivers. It probably wont work, as this seems to be a known error but it is sure worth trying.
I don't believe the memory stick came with anything to install.
Personally I NEVER leave something only on a USB stick, they are too easy to set down and lose or have walk away.
I now know better for next time 
They should be a back up copy not your only copy. If you have data that critical have you considered getting something like a maxtor external drive to use as a backup site?