I know that I am going to hate myself for asking this but what exactly is "steam". 

 

You say you try to start it so I assume that it is some kind of software?

Have you tried to reinstall it.  Go to Steam's website and download just Steam and see if it will run.  In the past week...there have been major tweaks to Steam.  Very 2D and very clean.  Perhaps just reinstalling it will fix your problem.

 

http://www.steampowered.com/v/index.php

 

Bob

I don't let Steam run in my startup group and have no problems running it!  It really sounds like something is missing or corrupt.  A reinstall sounds like a good idea.

 

Bob

Steam might be disabled in startup. Go to Start|Run|MSCONFIG|Startup tab. Look for steam in this list. enable the check box next to it. click on Ok. Restart and check. If you get any System Configuration Utility window, check the box, "Don't show this message again" and click on Ok.

 

 

This should fix it.

 

 

Otherwise, reinstall Steam.