After buying a new graphics (Radeon 6450) card and installing it in my computer. I start up my computer like I normally would and it boots up fine. The problem is that when it comes to the user accounts menu (where you choose admin or guest) the screen is completly black and you can see anything. I can press enter and access the admin account but, all that is available is the desktop background. Pushing start or (crtl+alt+del) or clicking the mouse does nothing. The only thing that works is right clicking the mouse. No programs will run, absolutly notihng.
Any suggestions or know hows?