just had an Arduino UNO bootloader replacement. Computer still won't recognize it
Just to clarify, you purchased an ATMega328P microcontroller with the Ardunio Bootloader already programmed into it? if that is the case, it sounds like the ATMega16u2 interfacce chip on your uno is bad. Its sits between the usb connection and the AtMega328 and convert usb signals to TX and RX serial data onto pins 2 and 2. 

You could measure your 5v on the board and make sure its still good. If its good, its probably a bad board.  The 5V may have gotten a spike from the motor.