Help.
Every time I turn on my computer he restarts again and again.
The system says overlock failure.
This week when I turned on my other computer it said the exact same thing!
How can I fix this problem?

I've never seen that message before. However, I have seen the message "overclock failure" on some boards when either the HD won't boot or the fan over the CPU heatsink is not running. Is the thing making any peculiar noises; or worse, is it making no noise at all?

Try resetting your BIOS. Is your system built on an AMD platform? Because often motherboards made by companies like Asus and Abit have protections built in that warn if the CPU is not set properly. Sometimes on a bad hardware failure, the BIOS will give that error, which means you just have to go into the BIOS and tell it what your CPU's settings should be.

Often it is the simplest solution to the most difficult problem.