I was hoping repairing the cut USB cable would do the job but alas nothing.
If you can solder some 30 gauge wire to D+ and D- the other two connections are easy.
- If not, get a new Pro Micro.
Looking at the schematic
here:
- Ground is ground, so
that connection is easy, but the others don't have direct connect pins.
- VBUS/UVCC from USB goes to SJ1, C6, and 32u4 pins 2 and 7. Soldering a wire to the "J1" label side pad should be fairly easy. (upper left of pic below)
- D+ from USB goes through R5 to 32u4 pin 4.
- D- from USB goes through R7 to 32u4 pin 3.
This guy did the repair and provides some useful pictures.
https://www.instructables.com/Fixing-an-Arduino-Pro-Micro-the-USB-Port-Came-Off-/
Am I missing some drivers or software for my PC to pick it up?
I don't know what firmware your current board uses, but the software libraries for the Leonardo series of 32u4 boards (Leonardo, Micro, Pro Micro) are designed to make these boards appear as a Human Interface Device (HID) mouse, keyboard, or gamepad that works with generic Windows or Linux HID drivers.
Scott