Computer wont start any ideas?

ok guys give him a break theproblem you may be facing would be due to

A(if you are stuck on login screen or computer restarts automatically)

1.corrupt os(reformat pc)

2.virus(reformat pc)

3.lot of heat is generated try adding liquid cooling and more fans

4.caps is on or in some cases off

b(if not able to start even little)

1.motherboard damaged

2.hard drive damaged

3.wire loose

4.bios corrupted

let me know if you get what is the problem

Try resetting the cmos battery to bring the bios to default settings, seems like you are being block from logging in might be a true virus , could be wrong a hard ware issue more than likely,the final solution reinstall the os could be a corrupt windows file deal with logging in to the pc .try a couple of things reset the hdd, swap the ram around, before reinstalling the os.

You have a virus. You will need to reinstall the OS, get all your goodies off first or you will lose them. If you take your machine to a shop, tell them to save your goodies, and I will bet new York to a brick you have a useless free AV

Well, I think the last resolution would be to reboot your computer but you don't want to do that unless you really have to because it erases all your memory. Have you contacted your computer brand makers? You might want to try that. Also, what brand is your computer? How old is it?

a couple reasons why. first, i need specifics...ok. so it does start. rite? when you say "wont let you log on your computer" you mean onto your user account?