How update BIOS if My dell cannot restart

Welcome to the Dell Community  @LukineskoNR 

To better assist you, the members and I would need the exact model number of your laptop/desktop???

1. Go into your BIOS.

Power-on the system and start tapping the F2 key to enter System Setup.

2. In Windows:

Hold down the” Windows “key and tap the “R “key.

Then type msinfo32 and hit enter.

Best regards,

U2

PLEASE DO NOT POST ANY SERVICE TAGS!!!

Dell Vostro 5568 Intel i5-7200U 8GB

I think that problem is in bios and I want update bios But I cant becuase if my laptop restart than freeze and i must turn off with button how can I boot usb and where can I download bios for boot usb ? 

@LukineskoNR 

Hold down the "D" key, push the power button, release the power button, wait 2-3 seconds and release the "D" key

The laptop should go through an LCD test of solid White, Red, Green, Blue and Black 2 or 3 times.

After completion it should try to automatically boot 2 or 3 times.

If it does not boot, then the next thing would be to disconnect the BIOS/CMOS battery.

Vostro 15-5568 Owner's Manual:

https://www.dell.com/support/manuals/en-us/vostro-15-5568-laptop/vos5568/removing-the-coin-cell-battery?guid=guid-6b6c66b1-7640-4533-a1bd-7487382b8271&lang=en-us

Disconnect the AC adapter and remove/disconnect the “Main” battery.

Disconnect the “Coin-Cell” battery.

Connect ONLY the AC adapter for 3-5 seconds.

Then disconnect the AC adapter.

Connect the “Coin-Cell and Main” batteries ONLY.

Turn the laptop over and open the lid.

NOW connect the AC adapter.

It should try to automatically boot 2-3 times.

Post your results.

Best regards,

U2