Did you format the hard drive during the windows install, or reinstall without formatting?
The motherboard BIOS is carried in a Read Only Memory chip, its contents cannot be changed without specialised reprogramming hardware (in many cases it can't be changed at all). During manufacture, the BIOS is transferred to a low power consumption (CMOS) memory chip, also on the motherboard, and its contents CAN be changed. When you make changes to the BIOS settings, you're changing the data held in this CMOS chip and not the ROM. A small battery fitted to the motherboard provides power to keep the CMOS data intact. these batteries last for many years BTW.
Check the motherboard manual or system documentation on how to reset the CMOS, usually it needs you to move a VERY small jumper or take the battery out for a few minuets, when power is restored the ROM contents will automatically be transferred to the CMOS.
Try setting your firewall/internet security settings to a high level.