Dell XPS15 99550 i7/16GB 4K 500 SSD - Last bios update -1.2.16 System BIOS - big issues
3 days ago I applied the latest bios update to my 1-year old XPS15, running latest and fully patched 64 bit Windows 10 public release.
A) plugin a rather simple USB-3 hub into the system prevents the laptop from Booting into BIOS, or if manages to do that
B) plugin said USB-3 hub after full windows boot, freezes both USB ports devices. The unfreeze can be overcame by unplugging the hub and then other device and then re-pluging both
C) after step B, windows explorer becomes very unstable and does not even show all the folder contents to some programs "open file" function.
D) the system does not recover anymore from plain S3 sleep, triggering a windows hard reboot.
I'm afraid the bios option to roll-back the bios version was not active, so I'm stuck.
Finally, the latest Intel diver published at the same time does not install cleanly after the bios update (although I managed to get it to show in the "program files" section.
I always apply the latest updates for drivers and bios promptly as main security policy and so far the system has behaved very well (Maybe with the exception of Hibernation from sleep time out, which always has been a bit faulty)