Asking a generic question normally gets no help, you need to specify model number. Did he last use it with an external monitor?
A friend has a Toshiba laptop running Vista. He just sent me this information about a problem that he is having...
"I can turn it on fine and it comes to my login screen where I can type in my password. After typing it in and entering, the screen looks as if it will go to the windows home screen, but just turns black. I can still bring up a task manager, but cannot do much else. I have tried taking the battery out, rebooting in safe mode, but nothing seems to work."
If anyone has any ideas as to what is happening and can offer some suggestions it would be greatly appreciated.