Hi Giuliano, Noom, Chris, thanks for your advice.
The weird thing is that after trying a bunch of times unsuccessfully, it seems to have come back alive again. With the Netduino Plus 2 plugged in, the ONLY thing I did was go into Win7 Device Manager and enable the 'Show hidden devices' option. I wanted to enable that option so that I could uninstall the driver. When I searched through the devices with that option on, nothing showed up in any of the categories. I closed the device manager and left my computer.
When I came back to my computer a little while later, the window for Control PanelHardware and SoundDevices and Printers happened to be open. To my surprise, I could see the Netduino Plus 2 under 'unspecified'. I thought maybe it was just to do with my 'Show hidden devices' adjustment, but then why wasn't my older Netduino Plus showing up? Sure enough the Netduino Plus 2 was back for real. I tried deploying and debugging a basic program and it seemed fine.
Giuliano, I really did try all the ports/cables combinations that were working for my Netduino Plus. So I have no idea why it just magically started working again. Noom, when it stopped working I was just iterating through different adjustments in software for a balance bot, I did think maybe I fried something even though I didn't see how I would have done so. Chris, when it wasn't working I did try forcing the bootloader mode with the button press but the device did not show up and the blue led did not light up.
Anyhow thanks everyone for the info. After the Netduino plus came back alive I was handling it wondering what the heck happened and was holding the bottom of the board and noticed it was quite warm. Currently it is plugged into USB but idle and it still seems warm. Is this normal?