Changing the default desktop environment and the default path

[PrinceOfHeaven]

I am using RedHat 7.1 with KDE as my default desktop environment(I set that when I was installing the package). So I get a logon screen with a KDE logo and all. But since I am interested in Gnome more I wanna set it as my default desktop and change that logo in the logon screen too, to the Gnome logo. So could someone please tell me how I can do that? and in which file I should set those variables?
I am also havin some problems since some of the programs installed in my menus arent given the full path. So I wanna know where I should mention that path without adding path command to each and every of those installed menus seperately. So all the users can run those files without giving the full path.

Thanks! :)
*PrinceOfHeaven*

[posterboy]

Open an xterm and type switchdesk. This will produce a list of all the desktops that can be found on your box. After selecting one, it needs a Xwindows restart, and that one becomes the default from there on.

Next, I would fix that in the menus entry, rather than altering the users path. Root, by design, has a different default path from users. All users should get /usr/bin and the like by default, and if they need access elsewhere, it may be unwise to give them a chance at a path they would'nt normally have access to. HTH, Ray