I been running the Thunderbird Portable program as my email default for some time now, for which I blame Joe Gleason. For which I've thanked him many times as well.
I keep it on a Cruzer 4Gb USB drive. Been oooooh so very happy with the system and do think to download it to the desktop fairly regularly.
This very day, only hours ago, actually, I fired up the computer and that thumb drive was missing from My Computer when I tried to open it. Its little light was dark. I removed it and plugged it in again. The light flashed once and again went dark. Computer did not recognize it as being present.
Tried another device in the same USB port. Worked fine.
Did a re-boot on accounta I know that's the first thing y'all geeks are fixin' to recommend. No change.
Have removed and re-inserted the drive several times. No change.
My new laptop ain't even been turned on enough to be set up, so can't check it there. Maybe can check it on owling partner's laptop when he gets back.
But are those things prone to failures after only a year or so of use? Might be a little longer than that, but not two years, for sure.