Could not find USB device 0x1781/0xc9f

I used to use a TinyISP to burn sketches to an Mega2560 because I didn't have the bootloader. I now have the ability to burn the bootloader and would like to switch back to burning skteches via USB. Any ideas how to do that? I changed the boards.txt file to use the tinyISP but I can't figure out how to change it back. I even deleted arduino022 and replaced it with a fresh install.

Thanks in advance