How Do I Turn On My PC at 4am

[Tursiops]

Can anyone recommend software (utility) that will allow my PC to boot up at a specified time and load ReplayAV so it can record a 4am radio program?
I'd imagine it can't be done from a Power Off state, but perhaps from Standby?

[carlobee]

I did a search in google for 'a software to turn on computer automatically' and it returned a few good results. you might want to check it yourself.