I'm running WMP10 (WMP means Windows Media Player) on a WinXp Sp3 system, but research suggests that this entry probably applies to most versions of WMP/Windows. I don't like WMP (or anything else) communicating with external systems without permission; and I blocked WMP's only listed entry by blocking wmp_setup.exe in Online Armour's [Configuration.Firewall.Programs] listing. The system would run run fine for a while, but would eventually generate an exception. I extracted the following info from one of the resultant Event Viewer entries.
Event 26 Application popup: oasrv.exe - Application Error : The exception unknown software exception (0x0eedfade) occurred in the application at location 0x7c812fd3.
The system would lock up in such a way that I was unable to access the Task Manager or Online Armour. I wasn't able to reset the system, and usually had to pull the plug to recover. Testing showed that I could avoid these problems by disabling Online Armour. Subsequent research and testing showed that WinXp ALWAYS locks up if you try to block wmp_setup.exe.from accessing the internet. So this problem wasn't really Online Armour's fault: It was just the middle man. The bottom line is this: WinXp will eventually lock up if you try to block wmp_setup.exe via a firewall (eg. Online Armour).
Further research shows that you CAN prevent wmp_setup.exe from accessing the internet as follows.
Open the Microsoft Management Console (MMC) via [start Menu.Run]. Type in "mmc", and press ENTER. Select [File.Add/Remove Snap In...]. Select [Add...] from the [standalone] tab. Select [Group Policy] from the snap-in's selection menu. Select [Finish] in the Welcome-To-The-Group-Policy-Wizard. Close that window. The Group Policy snap-in will be added the MMC console. Press OK to show the updated MMC console. Click on "+" signs to open up [Computer Configuration.Administrative Templates.Windows Components]. Select [Windows Media Player] in the left panel. Right click on [Prevent Automatic Updates] in the right-hand panel. Select [Properties] from the drop-down menu. Select [Enabled] for Prevent Automatic Updates. Press OK, and close the MMC console.