An educated guess (Timur Fanshteyn): New Sansa e260 + USB connectivity through a keyboard = almost system rebuild...

I just got myself a Sansa E260 MP3 player. A pretty good deal for $95 at Buy.Com after Google Checkout

Its a pretty nice device. Plays everything I need it to play - WMA, MP3, Video (after conversion - pretty annoying), Images (After conversion - again pretty annoying), Radio. The UI is OK. Reminds me of a mix between Windows Media Center and IPod. I think IPod is easier to navigate, but Sansa is still not bad at all. For $95, its a great little toy.

I connected it at home to me Vista laptop with no issues at all. Everything worked like charm. So I brought it to work and decided to copy the latest hanselminutes podcast to it. That's when the trouble started.

I have a media USB keyboard from Dell. Nothing special, a default keyboard that came with the system. It can (or rather should) act as a USB hub providing 2 extra USB plugs. I should mentioned, that I never used it as a hub before, and just assumed that it worked. I plugged the Sansa in, and ..... Nothing happened. Media player did not show the device. Running "Add hardware" wizard showed a nice little dialog: "you can install only one device at a time". Rebooting didn't help. Google search found a few articles about the error with almost all of them pointing to a specific registry - "Remove the key and reboot". Well.... Being adventurous - I do exactly what the posts suggest. After the reboot - I see a "Windows XP Setup" screen as the first window, Before any network logons, startup scripts, etc... After rebooting in safe mode, windows brings up an error message: "Setup can not run in safe mode" and reboots. The "Windows XP Setup screen" starts up again and system looks hung up, with only occasional HardDrive light. After 30 minutes or so, I decide that I might have to rebuild it - or at least repair from the DVD.

In another 30 minutes or so, the system finally starts up, and seems normal. However, the original problem is still not fixed. The Sansa still does not connect, the "Add new hardware" wizard still does not start up. So I decide to go back to basics. Crawl under my desk, and plug it into the back of the machine. Hooray, it works like a charm. The system recognized it within 10 seconds, brought up WMP, and showed it as the device.

So... Lessons learned:

Minimize experiments unless you have spare machines or multiple harddrives. (I have both so I was able to work while my main system is down, and rebuild OS still keeps all my important files intact)
KISS - Keep it simple. When you need to plug in the new device - don't use the USB keyboard as a hub if you never did it before. Go straight for the USB port you trust.
DO NOT SCREW AROUND WITH REGISTRY. Especially based on forum posts unless you completely trust people who trust them