Bluetooth card vs dongle

I used to have a bluetooth keyboard, with a Windows PC and a USB bluetooth dongle, but sometimes I was unable to use the keyboard to unlock the computer - it was like the PC needed to wait for Windows to be unlocked before loading the bluetooth drivers or something. It was weird, as it didn't happen every time, but it became such a problem that I got rid of the keyboard after a few weeks. I'm wondering if a bluetooth card installed inside the PC would avoid this issue or whether it would be the same. Can anyone advise?

Question by danwellman on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.