How do I ask the PC to restart & boot from DVD

I have a DVD of a OS but i need to restart to set it up right?How would i go about doing this?

If the DVD is bootable all u should need to do is insert the DVD and then restart the computer.

Make sure the BIOS is set to read the DVD drive first though.

Maybe someone else will explain more because im too effing tired right now.

if its bootable, like mr blunt said, there should not be anything you have to do special

if its not, go ahead and put the dvd in, restart
when you restart your pc, hold down the delete key (most likely, but some BIOSes use a diffferent key),
and your pc will go into the BIOS menu
find the boot menu, probably in advanced configuration, or if your lucky theres a boot tab,
set the "boot from cd-rom" to the first boot, hit F10 to save and exit, done

sometimes its f10 or f11

maybe even f12 but once you find it change it to boot from dvd first

Thanks for the help people