Component Services snap-in under Administrative Tools allows you manage COM+ apps on different computers on your network. This’s done by adding computer to a list which’s then saved for next time you open app. While this means you don't need to keep adding computer, it can also cause app to appear hung if computer in the list no longer exists. In Component Services snap-in, if you try to add computer name to Computers node that doesn’t exist or isn’t responding, or that ceases to respond at some point, MMC may become unresponsive. WorkAround 1: 1. Open Component Services Start -> Run -> dcomcnfg or Control Panel - > Administrative tools -> Component Services. 2. Drop down into Computers node from Component Services node. 3. Make note of computer names in this list (apart from My Computer) that’re no longer available on network. 4. Close Component Services (you may need to kill app from Task Manager if it isn’t responding). 5. Open HOSTS file in a text editor (the file can be found in \System32\drivers\etc\; backup a copy of the file first) 6. Add entries for each computer name you noted, and assign each loopback IP address (127.0.0.1). This’ll result in a quick valid response from each computer name when plug-in tries to access it. It won’t be real IP address of unavailable computer, but MMC doesn’t know that. 7. Save HOSTS file. 8. Reopen Component Services and drop down to Computers list. 9. You may take a bit of time, but now you should be able to select invalid computers in list and remove them. 10. Once the invalid computer names are removed and plug-in is responsive when opened, edit HOSTS file again to remove entries you've added.
For workaround 2 refer, Component Service MMC hangs if a remote computer is offline