How to update bios in Sony Vaio Vgn 5320e?

I have a Sony VAIO VGN 5320e laptop ,I want to know that how to update the bios in my Sony laptop, and I also want to ask that from where can I download the Sony VAIO bios update

I would like to recommend that you should try to download bios update from the official site of your laptop manufacturer, and before downloading you must ensure that the bios update you are downloading must be of latest version and not the one that you have already installed .

like all other computers even your Sony vaio laptop has a bios, bios is a service that checks whether all the components within the system in proper working state. Bios allows the system to start up only after this checks are successfully completed so that in this case if the components are defective, additional damage to the components can be avoided.
When you are updating your bios you must ensure that all your application running in the background have been terminated, updating the bios would increase the system performance and reduce the start up time.

I had a Sony vaio laptop, I want to know that whether I will lose data or not, if I’ll update the bios to my Sony laptop, if yes how can I prevent this. Please suggest me

if you will update your bios to your laptop than you may be lose your personal data, so it is better to keep some important points in your mind while updating the bios which are mentioned below:
1. Always keep backup of all your data
2. Always check the version of bios you are updating and
3. Verify CMOS battery.