i've read posts on this topic but i couldn't find a solution for my problem, so i hope you guys help me out. my computer randomly keeps on shutting down. thats the 1st problem. the second is that when i turn it on, it goes for about 5 seconds before it even brings the logg on screen it restarts and restarts, and restarts by itsself. and i've read to get anti virus and scan my computer and i already have an anti-virus, but i can't scan for anything because its not going to the logg on screen! i know it is very confusing, but i really need help! before my dad kills me! :D

When it shuts down does it display an error message or just power off. If it's powering off you may want to check and see if all the cooling fans are working a thermal switch might be kicking in cutting the power

it tells an error message. it says NTLDR is missing. but i don't know what it is and how to fix it. :(

You need to put it back. Boot up a windows install disk press R at the first screen for repair login to the repair console type in

fixmbr when that is done type

Resart computer