Dont do bios upgrades. You can better try to backup your files as fast as possible and try to do a clean windows install. These problems can occur, because of virus infections. Sometimes it even renders you unable to use windows explorer. Best is to install a browser as fast as possible, so that when you cannot enter the shell of your computer, you can use a browser to backup files, by starting it through the taskmanager.
A clean windows install will most likely solve this problem. Do not alter bios, unless its a last resort. Firmware updates can be very dangerous to the functioning of the hardware. Besides bios updates are rarely effective, unless you have new unrecognized hardware, such as a newgen processor, for an old mobo with the right socket.
Something very useful if you havent done it yet: Make different partitions (such as c:\ and d:\) at your windows reinstall. This was your os is seperated from your precious files.