I've spent that last 2 weeks trying to get my xbox to recognize my computer, based on EVERYTHING this site says from before, and I've finally solved it thanks to a helpful dude @ xbox. My computer saw the xbox, but not the reverse. Network settings were fine but something was still wrong.
(Windows XP, using Media Player)
Turns out when the computer sees the xbox and the xbox can't see the computer, it tends to be a CORRUPT library file.
Looking back, when I was adding my 1400+ video files it would stall out and took 3 or 4 go's at it to add them all. Should have been a hint.
So the previously mentioned stuff about DRM folder deletion worked temporarily, but I have found a PERMANENT fix (for my situation and possibly everybody elses who CANNOT find anything else that will work)
(this is from xbox help)
Click the Start Menu button and RUN..
Type in services.msc and hit OK
Make sure the following are set for AUTOMATIC and are STARTED:
-SSDP Discovery services
-Fast User Switching Compatibility
While you're at it, STOP the service called Media Player Network Sharing Service
Leave this window open, as you will need it to restart this service in a sec
-Go to explorer's top menu >> Tools/Folder Options/View/
CHECK "Show hidden files/folders"
UNCHECK "Hide Protected operating system files"
C:\Documents and Settings\Administrator\Local Settings\Application Data\Microsoft\Media Player
Delete EVERY file. Leave the folders (Art Cache and Transcoded Files Cache should be the only 2)
Then go to
C:\Documents and Settings\All Users
and DELETE the folder called DRM
NOW! Go to the Microsoft DRM Licensing site found here
(in internet explorer only)
and click UPGRADE
Go back to the Services window and restart Windows Media Player Network Sharing and make sure it's also set to Automatic.
Re-add media library, restart computer, restart xBox and I hope this helps.
If not, call Microsoft