shutdown during a bios update

Well, there is probably nothing you can do.  There are several things during which you should never disconnect power - a BIOS update is one of them (just like the warning during the update said).

You can try clearing the NVRAM/CMOS ... I don't think this system has jumpers, so just power off, unplug, and remove the coin battery for 10 seconds or so.  It probably won't work and you are looking at a motherboard replacement.

Contact with nearest repair shop for better solution either it can be repaired or replace the board

My XPS 8500 gave me a sudden message for a download  and I clicked it to see what it was, and it was a bios update. After it started downloading I noticed it started to say it was taking down old software ,which really scared me since I had a history of viruses on other computers. I became scared thinking it could be a virus and shut my computer off mid download. Now my computer wont turn on and the light from it just blinks.

You've "bricked" the motherboard and it can only be repaired at a special facility. It's not a good idea to have the BIOS automatically updated, and that's why I always update mine from a DOS-booted device.

A cheaper alternative to a factory motherboard is an aftermarket Ivy Bridge product, but you'll have to re-jig the wiring to adapt it. I can advise, because I have done this both ways.