Originally Posted by GoSharks
What OS are you using? If you are using Win XP, it does not recognise MTP, and therefore will not recognise the Fire HD.
oops, looks like you have Win 7...sorry, can't help. Have you tried the Device subforum in the Calibre Forum?
I did post in the device forum. Goyal said to reboot both - which worked once - now it isn't working again. Tried rebooting together again last night and nothing. Such a pain because ALL of my books are in epub