so i got a toshiba c660 satellite laptop. everything was good until one day when i was using my laptop, it suddenly shut down. then i try to open it again, while in the starting windows logo, it shuts down again. i tried to open it again, then the launch start up repair command showed up. i tried the start up and i can use my computer again for long hours. but after letting it rest for few hours, the same thing happened again. what could be the main problem? and what should i do in order to fix this? and another thing when i use capslock the key 4 r f and v do not function. but if i hold shift i can type 4 r f and v. is that related to the sudden shutting down? please help me. thanks in advance.