Navigate the the location below in your registry and make the corresponding change based on the values below.

0: no support for IP multicasting.
1: support for sending but not receiving. 
2: full support for IP multicasting.

Create or edit the existing DWORD value (string value for Windows 98) named "IGMPLevel" and set it to either 0, 1 or 2 accord to the values above. 

Restart Windows. 

Key:[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP]
Value Name: IGMPLevel
Data Type: REG_DWORD
Data:0, 1 or 2 (Default = 2)