I don't use Steam but have heard that you can change the install directory to something like C:\Steam:
Its simple, all you need to do is uninstall steam completely yes you will have to re-install your games again but thats the only downside to it.
Then go to the steam website and you will see in the top right hand corner of the web page "install steam" click that and then you will get to choose where you want it installed, same as choosing a destination when installing a non-steam game .... the rest is simple from there on.
Bookmarks