The startup BIOS screen doesn't show up

[computerbeginner]

Hi, everyone

Just so you know, I am a complete beginner with computers.
I just bought my first PC from iBUYPOWER.
Lately, I became irritated with my air fan's noise volume and decided to lower its work load and since I don't play hardcore games for 4 hours straight, people have said it was OK.
To do that, they told me to go to the BIOS screen but the problem is, when my computer first boots up, it goes straight to the Windows log in menu. The loading screen to access BIOS from never comes up. The more I try to research on the subject the more frustrated I get.

If anyone has the time for a step by step guide to fix this, it would be greatly appreciated.
Thanks!

 

[Phillip Corcoran]

If you know the correct key to press for BIOS Setup, it should still work if you press and hold it down as soon as you switch on.

I can't tell you which key it is since I don't know make and model of your PC.