After Windows 10 upgrade I can no longer access BIOS

This is a common problem in all Lenovo laptops. I also have faced this problem so many times. For solving this please go to the link(link of official Lenovo's support site) and download latest bios setup and install it. It will update your bios and all will be all right. Download bios set for window 8.1 and install it. The manual also is given in PDF format. http://support.lenovo.com/in/hi/products/laptops-and-netbooks/lenovo-g-series-laptops/lenovo-g580-notebook

Update:

After this again the same problem happens with me but this time I already have latest BIOS version installed in my system and the Lenovo don't allow the installation of same or lower version of the BIOS in existing latest BIOS. So I stuck there and can not do anything. I also approached to the Lenovo service center but they are also helpless they suggest me to change the motherboard which cost me around 10000 INR.