Issues after BIOS 2.7.0 Update

There was an urgent BIOS update request on Dell SupportAssist tool, post BIOS update WIFI network selection, Sound, Battery buttons are not working. I'm using Dell Vostro 5481. 

Dell Pro support is unable to fix this issue and asking to reinstall OS as a solution. As per Dell, this issue is only in one PC, I'm sure I'm not the only user in this world having Dell Vostro 5481. If anyone else has similar issue please mention it so it will be easier for Dell to troubleshoot and fix it for entire users across the globe.

Dell Inspiron 5480/5488/5482/5580/5582 and Vostro 5481/5581 System BIOS - 2.7.0 - 15.7 MB - Urgent - Installed