my dell inspiron 1545 runs on vista and i tried to log on but when it went to log on i tried to move the mouse to my icon. it wouldnt move. i tried to hit the over keys still no movement. when i turn it on if i hit F12 i can move the keys and run tests but it wont log in. my mom and i are not happy because we have used 2 of our 3 uses of microsoft works ofice student that costed us $150. i really need help. does anyone know how to fix this?