has it done a check disk right after it show the windows start up screen? I think it would be that your hard drive is losing sectors. Also you have anything magnetic near your tower? I dropped a...

If you're getting a master boot sequence failure, that means you have corupt or damaged windows systems files. And the fact that it was read my another computer as an external storage device only...

Yea try a system restore or a recovery. If neither of those work then what you're left with is nothing else than a destructive format. Sorry if this isn't more helpful. But that is the cut and...

Black screen with the white cursor flashing in the corner usually indicates a master boot sequence failure. Try testing your hard drive on someone's computer. If it's registered by the other...