This article will help you in Disable or Enable devices from command prompt. And also this will discuss about the error u may likely to encounter.
It will be really good rite, when you can disconnect your modem or internet connection in one click after you are finished with it. This article will help you to do that.
First you need to have devcon.exe. An alternate to device manager which can be run through command prompt.
Download the devcon.exe from the below link
http://support.microsoft.com/kb/311272
Once you downloaded the devcon exe file, extract the exe and paste it inside c:\windows\system32 folder. That's it you are ready to run it.
I've read the above procedure in a blog, and wanted to try it. ...