Question about updating (flashing) the BIOS

I have just bought a Dell Inspiron laptop. On the Dell drivers site it says that version A05 update for my system BIOS is recommended. The version on my laptop is A02 so its quite a bit out of date.

If I update my BIOS will this ruin future Windows 8.1 reinstallations. Because it is an OEM system I don't have installation media .. I reinstall from the factory image. At the moment when I do a clean reinstallation Windows 8.1 gets installed and Windows Activation is done automatically. Activation is tied to the BIOS.

Can you flash/update the BIOS without affecting future reinstallations and the current automated Windows activation method or does updating the BIOS completely ruin that method