I have the same exact problem with my Harmony 720. My connection is hardwired into my cable modem, and I tried USB and network adapter both.
I'm curious if others have not been able to update his remote? My PC WILL NOT download the update file (Update.EZHex), either manually to my desktop through the web or through the software. It worked fine the first night I got it; I updated the remote several times with no problems. Then it suddenly stopped updating, and hasn't worked since. It goes to the update status screen, then stays at 0% and never moves. The only way I got the remote working at all was to have tech support email me the update file. When I click logout after waiting awhile, the status meter jumps up as if it were updating, then the software closes and nothing happens. Here is my system and what I have tried:
No virus/spyware protection, Windows firewall turned off
I've tried with Firefox / IE
I've tried uninstalling the Harmony software and reinstalling
Scanned for Spyware/Adware
Defragged harddrive (I was really reaching)
Firmware updates to the remote no problem
Communication check with remote works no problem
The update file gets to about the 400-480K mark, then just sits there. I actually let it sit all night at one point and it never proceeded further. I have no images in my setup.
I like the remote, but for now I have to do updates at work and email the file home. Real PITA!!! If anyone has experienced this or has any suggestions, I would appreciate it. I am at my wits end. Level 2 tech support was sympathetic, but basically said it was a problem with my system. I'm really stuck here. Thanks in advance for any help.
Frustrated in KC