I need some with help Sierra bros PLZ!

[DJRipper]

So I have a GA-Z170N-WIFI Mother board and it was up and running Sierra no problem, but the wifi wasn't working so I tried to (with my limited knowlegde) adjust the config.plst and **** the bed! It won't boot up. I reset the CMOS and tried to start from scratch but every time I try to load the flash drive (or the SSD) there's just a big white circle with a line thru it! I'm new to this whole DIY computer thing so ANY help/ideas would be awesome guys! THANK YOU SO MUCH!~

 

[DJRipper]

I tried checking the BIOS and all my settings are the same as the first time when it worked, but every time I try again it makes another partition to my SSD in the BIOS, so maybe its not booting from the USB? Does that make sense to anyone? Anyway to fix or avoid this? THANKS AGAIN!~

 

[BreBo]

I tried checking the BIOS and all my settings are the same as the first time when it worked, but every time I try again it makes another partition to my SSD in the BIOS, so maybe its not booting from the USB? Does that make sense to anyone? Anyway to fix or avoid this? THANKS AGAIN!~

Check this topic to get rid of the boot entries:
[GUIDE] Remove extra Clover BIOS boot entries & prevent further problems

According to this topic upgrading your BIOS to F20 will fix flooding the BIOS with excessive boot options:
PSA: Gigabyte F20B BIOS changes