"Missing Opperating System" error when 3005pr Port Replicator plugged in

[Tim_Myth]

One of my end users has an HP 3005pr Port Replicator for his HP ZBook 17 G3. If he attempts to boot (not restart, wake from sleep, not wake from hibernate, etc.) the laptop with the port replicator plugged in, he gets a Missing Operating System error. The OS is Windows 10 Anniversary update, but I should point out that a missing operating system error kinda means its not a driver/os issue. We have updated his BIOS to 1.12, but the issue still occurs. If we unplug the port replicator, the laptop boots fine.  And if you plug the port replicator in after the laptop boots, the port replicator works.

[Tim_Myth · Accepted solution]

After quite a bit of searching, I found out that this port replicator has integrated flash memory containing the drivers. Setting the laptop to boot to HDD first fixed the issue.