Hi all,I have a problem getting back into my bios settings as i have no display,I was in the setting in Primary Graphics Adapter and changed it from internal to pci which was wrong but now i cant see my screen to be able to get back into Bios settings,Please help

Is the video plugged back into the onboard? It should auto detect which controller has is connected when you reboot.

If it doesn't and you want to reset your bios changes back to default an easy way to do that is unplug the power and remove the small watch battery from the motherboard for 30 seconds. Then replace the battery and power and you should be good to go.

Agree with Zelkea but some of the things that will happen to the machine on restarting will depend on the age of the machine and also on the modernity of the biuos. If it is an old machine it may not detect some things and you will have to do quite a bit of resetting manually once you get back into the bios.
If you password protected the bios you may also need to sue that or reset it.