My Macbook Pro 15 inch (2,2, 2007, OS X Lion, last version, 3GBram) starts up but coming to the login screen, all strange colors appear and the screen freezes. Unfortunately my DVD drive also broke some time ago, so I can not run apple hardware test from the install DVD. When I start in safe mode, it's possible to log in, but there are some strange stripes next to the mouse pointer. Does anyone know if this is a hardware or software related problem? How can I rescue my data in safe mode? thanks in advance!!