Before you start: make sure the right ports are open, your files are shared in Windows Media Player, and sharing is activated on your network
In my case everything was working until one day, it simply wasn’t.
My pc could still detect my Xbox 360, but my PC would not show up in the video/music/… sharing area on my Xbox 360.
If this is the case for you too, then this could possibly be your lucky day, as I found how to fix it.
To fix this problem I did the following:
First: run http://www.netflix.com/pages/previews/resetdrm.exe and remove your DRM files
Then: Go to http://drmlicense.one.microsoft.com/Indivsite/en/indivit.asp and click “update”
1.Open a command prompt (be sure to right-click and choose “Run as administrator” or you will receive a “system error 5 has occured. Access denied.” error. You can do this by right clicking on the file here C:\windows\System32\cmd.exe)
2.Type net stop winmgmt. If it warns you about other services stopping just type Y to continue.
3. At the command prompt type
to delete this folder and all its contents
5.Once the system has rebooted open a command prompt and type net localgroup administrators NetworkService /ADD
Boot up your Xbox 360, go to f/e the video part and select “detect computer -> test connection”, your computer should now show up in the list.