Update BIOS on Old Laptop (Inspiron 1575/Inspiron N5050 )

This was bought as a Christmas present for my sister in 2011. About once a year I give it a "once over" to keep software up to date, and a couple of years back I swapped over the WiFi mini-board so that I could upgrade it to Windows 10.  It's been great most of the time, perfectly suiting my sister's light-user needs. However, since installing the W10 the Creator's update a few days ago, 2 of the 3 USB ports no longer work. I want to see if a BIOS and/or chipset driver upgrade will fix this but the BIOS flash update programme to install A14 will not run under Windows 10. (Gives error code 00000406). Any ideas on how to force a BIOS upgrade in this scenario?

The machine is an Inspiron 1575, exact version is Inspiron N5050.

Thanks in anticipation

Steve