Slow boot before bios

Hi there, so recently I noticed a small problem with my pc. Usually when I start it up I just leave the room to do something else so I didn't noticed it until today. When I power my pc it takes some seconds (~20 sec or so) to beep and load the bios. I just see a black screen and then after 20 sec I see the bios letters I hear the beep and everything goes fine. Windows start very quickly and pc runs fine. I would like to know the reason why I hear the beep so late because I remember hearing it almost instantly when I booted the pc in the past. I didn't make any hardware changes lately. So what do you think is the problem??

Some things I already done trying to solve it are:
1) I removed all cables and pressed the power button for 15 sec. I read this somewhere that it might help.
2) And I reset the bios settings through the setup.

Any other suggestions? Thanks in advance.

 

Check if it is looking for cd/dvd rom first- if Hard drive is not first listed, it will check others first

 

No, its not this, it doesnt even go to bios, so it doesnt check the divice to boot yet. Also I noticed a new problem now. The back and the base of the pc case has electricity and I don't think it is static. I barely touched it and my arm got zapped all the way.

 

I would unplug it and if you know little about pc's and get a proffesional to check it out- otherwise , check the plug for an earth connection- the next zap might be nastier.