Close port 135 by disabling DCOM in Dcomcnfg.exe


Click on Start> Run> and enter: C:\WinNT\System32\Dcomcnfg.exe, then click on the Applications tab. Many programs "support" Distributed Communication (DCOM) but hardly ever use it. This includes such programs as Windows Media and Wordpad, which are designed to be used across a network. As you scan this tab, look for third-party applications that might actually require network support, as opposed to those that simply support it. To determine if these programs really require DCOM, you must disable it, run those programs, and see what happens. NOTE that it is probably only necessary to look at third-party programs here; Microsoft programs designed to run on a non-networked, stand-a-lone computer (Office, etc.) are usually written to support but not require DCOM. To disable DCOM, go to the Default Properties tab and uncheck the box labeled "Enable Distributed COM on this computer".

Reboot, and try running the third-party programs NOTEd as above. Chances are good that everything will still run correctly. If not, go back and enable DCOM again. As you re-enable it, also go to the Default Protocols tab and remove all protocols except "Connection-oriented TCP/IP". This won't make your system much safer, but it will reduce the number of connection methods you have to keep an eye on.

If you do not have to re-enable DCOM again, then on the Default Protocols tab remove all protocols. You won't need them, and that should stop the OS from listening on Port 135