[Optimus V Android Development] El Schisne:
Okay, I'm about to file an issue at github about what methods don't work re: USB tethering on Windows, but I thought it would be nice to have a post about what method does work. I finally figured out a big ugly workaround for Windows 7. Note that this is necessary only the first time you plug it into a particular computer; thereafter, it will Just Work.

Windows 7

1. Install LG United drivers. They're on LG's website and linked to directly in the OP. Also download, but don't do anything with, blarf's INF file in the OP.

2. Plug in your Optimus; let drivers install. They will take awhile and may say that not all of them installed correctly. Ignore that; they did.

3. Go to Device Manager. Start the Add Hardware wizard by clicking Action -> Add Legacy Hardware at the top. We're going to manually add the driver.

4. Click

Next ->

"Install the hardware that I manually select from a list (Advanced)" ->

select Network Adapters on the list and hit Next ->

select "LG Electronics, Inc." on the left and "LG AndroidNet NDIS Ethernet Adapter" on the right; hit Next.​

It will say the driver installed but might not work properly.

5. At this point there should be a new device in Device Manager under "Network adapters": "LG AndroidNet NDIS Ethernet Adapter." It will have a yellow exclamation-mark sign on it. Right-click on it and select Update Driver Software.

6. Click

"Browse my computer for driver software" ->

"Let me pick from a list of device drivers on my computer" ->

click the "Have Disk..." button ->

"Browse" to where you put blarf's INF file ->

click through the "driver is not signed" warnings​

It will say Windows encountered a problem because the device cannot start. This makes sense because tethering is still turned off on your phone--and the reason it's turned off is that you needed the driver in order to turn it on in the first place.

7. Turn on tethering. It will go off again. Turn it on again. This time it should stick, and the device listing you created above (in the Add Hardware wizard) should be replaced with two listings in Device Manager, both named "LG-VM670 RNDIS Ethernet Adapter." One will have a yellow exclamation-mark sign. It's safe to uninstall that one, although it's not hurting anything.

8. Tethering works!

tl;dr Install the LG NDIS driver manually to make Windows see it, then apply the INF to make it actually work.

Windows XP

1. Install LG United drivers and download the INF.

2. Plug in your Optimus; let drivers install.

3. Turn on tethering on the handset. It will go off again, and the Found New Hardware wizard will come up. Using the same "Have Disk" button mentioned above, point it to blarf's INF file and let it install.

4. Turn on tethering again.

5. It works!

I should note that according to the README for the INF file, you can install the INF by just right-clicking it and clicking "Install." This did not work for me, so I provided the Windows XP guide.

Caveat

In Windows XP, USB mass storage et al. might not work properly once you turn off tethering. If you turn tethering on and off multiple times, it may mess itself up to the point that you have to

1. uninstall the LG drivers

2. plug the phone in with no drivers (just to be safe; you can probably skip this, in reality)

3. reinstall the LG drivers

4. repeat the Windows XP process above.

This is not necessary on Windows 7. There, all other USB functions should work normally once you turn off USB tethering.