BIOS (Basic Input Output System) from http://en.wikipedia.org/wiki/BIOS :
The BIOS software is built into the PC, and is the first code run by a PC when powered on (‘boot firmware’). The primary function of the BIOS is to load and start an operating system. When the PC starts up, the first job for the BIOS is to initialize and identify system devices such as the video display card, keyboard and mouse, hard disk, CD/DVD drive and other hardware. The BIOS then locates software held on a peripheral device (designated as a ‘boot device’), such as a hard disk or a CD, and loads and executes that software, giving it control of the PC. This process is known as booting, or booting up, which is short for bootstrapping.
A simple description: it provides the interface “translator” between a PC’s specific hardware and the PC’s operating system (OS) software.
Now that you’ve updated your OS to Windows 7, you might want to consider updating the BIOS to streamline the interfaces with the newer OS (however, it may not make any really recognizeable differences depending on how your BIOS was generated in the first place).
The update process is not usually difficult, but must be followed exactly or the PC will no longer work at all without bringing in a specialist to bring it back up.
The usual process is to download a compressed update file from your MOBO manufacturer’s website onto your PC’s hard disk drive. This compressed file is then expanded to a memory device that is checked for data during the PC boot process used to load the PC’ s OS: floppy disk, or CD-R.
Once this file is decompressed onto a “boot device” (e.g. the floppy or CD-R), the the PC is restarted with these decompressed files present in the boot device. These files then lead you through the update process on your PC screen.
If the process then runs properly, this set of files first erases the existing internal BIOS from an internal Programmable Read Only Memory (PROM), and then completely uploads the new BIOS into this internal PROM.
Obviously as this process is designed to first erase the existing BIOS “firmware”, the process must start and be allowed to run to completion, or the BIOS files on the PC will either be gone or corrupted; meaning, your PC cannot boot up and run. If the installation or update process is followed explicitly, everything will turn out fine (I’ve done it several times for various PC’s).
The fundamental idea: start the BIOS update process with the right files for your specific model and build revision of your MOBO, and don’t interrupt it! Let the process run until the BIOS update is successfully installed; the update program will tell you when that has occurred on your PC screen.
If this explanation gives you pause, then it’s probably wiser not to attempt it! However, if you continue to have instability problems, you might consider hiring an IT pro to have a look at the machine and determine if it may be related to the BIOS, and perhaps let them update it.
Hope this helps!