Pro Micro woes

I have been trying to upload and run programs on a pro micro (AM32U4, 5V, 16 Mhz version) but it shows up as Unknown USB Device (Device Descriptor Request Failed) despite many attempts to install new drivers. When I try to upload a program it just times out - only Com1 is available, the board name & comm port never comes up as an option.
I tried resetting (no switch, just short out Reset to GND pins) but that also has no effect.
I seem to have spent the whoel weekend trying to resolve this and got nowhere.
You are my only hope for sanity and a good nights sleep.
Any ideas what I could try next, or what further info I need to provide you?

Is this a new board or a board that you used in the past?

Is it a clone or an original?

If it's a new board, send it back to the seller or try to burn the boot loader. If it's a previously used board, try to burn the bootloader.

its a new board but i soldered pins into it now, they prob wont take it back. Burn the bootloader means I need to buy a UNO? Or can I do it via Windows software? Even though windows wont talk to it on USB?

You need another device to program the boot loader; can be an Arduino or a dedicated programmer.

So if this one is now beyond hope, its pa better and cheaper option for me to send this one back and buy another Teensy which worked fine for me with no issues. Ive wasted enough time on this nuisance chip.