Please see my comments to the question. Formally, the answer would be: use the Remote Desktop feature. The remote computer you want to control should run the RDP server. And the computer you want to connect and use for the control should use the RPD client. Please see:
http://en.wikipedia.org/wiki/Remote_Desktop_Protocol[
^],
http://msdn2.microsoft.com/en-us/library/aa383015.aspx[
^],
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q186607[
^].
However, this is not how remote administration is really done.
First thing to understand is: you cannot just connect to some arbitrary computer. The computer can be remotely controlled if it runs appropriate network software to listen to the administrators' connection and obey the commands.
Please see:
http://en.wikipedia.org/wiki/Remote_administration_software[
^],
http://technet.microsoft.com/en-us/library/ee449475%28WS.10%29.aspx[
^] (for example).
The last note: this is all really off-topics. You are acting as a user, not a developer. If you want to develop your own administration tools, you need to develop some Window Service, and install it on the computers under controls.
—SA