Just for future reference so people reading these threads don't get super confused, your computer won't recognize your phone through
adb commands unless you are in
adb sideload through your
custom recovery, or if you're booted up and running in an operating system. You could also use
adb push commands in your
custom recovery. This has nothing to do with drivers or whatnot. If in
bootloader your device isn't recognized through
adb commands, that's completely normal, because it never would be, but your device should be recognized in
bootloader with
fastboot commands.
IF your phone is NOT recognized in your booted up phone, or in adb sideload through your custom recovery, or with adb push commands in your custom recovery, with adb commands, then you have driver issues.
ALSO IF your phone is NOT recognized while in bootloader, with fastboot commands, then you have driver issues.
To answer the OP's question:
If you have an unlocked bootloader and you are in TWRP, you can mount your phone onto your computer and copy and paste the rom zip onto the phone and then install it through TWRP once on the phone. If that doesn't work, then you can try using adb push commands while in TWRP (or maybe need to be in adb sideload through TWRP) to push the rom to your sd card and then run it through TWRP. If that doesn't work, you can also try flashing the rom zip through bootloader with fastboot commands, but all these commands might be device specific, that's why I won't tell you the commands I know for the HTC One X, but the processes are the same no matter what. Hope that helps