I'll lead off ... since I see that Amazon has finally updated their Kindle Fire HD Support page .... (
http://www.amazon.com/gp/help/custom...deId=201022260)
[this drove me nuts for almost a week!]
[the page originally said you had to be running Vista or 7 to access your Fire HD via a USB cable]
If you are trying to connect your Fire HD to a PC running
XP, you HAVE to update to Windows Media Player
11 - in order to see the folders and move stuff from your PC to the Fire HD.
Otherwise the Fire HD is recognized only as a Media Playing device and you can't move files onto it.