For the sake of clarity:
USB mode is for transferring files to and from that part of the TP. Novacom drivers are not required for that as the machine simply presents itself as a USB drive and the standard USB drivers are sufficient.
The Novacom drivers are needed to communicate with the webOS system - actually installing apps and patches or issuing commands to the machine. This process does not require USB mode. It usually requires the webOS device to be in developer mode - accessed with a code. I'm concerned that you are trying to 'see' the TP as a USB drive on windows. This doesn't happen in dev mode, only in USB mode.
It's not clear to me that USB mode is even possible until the activation has been bypassed and you don't need it to bypass activation. The connection instructions in this thread are:
If you are unable to run the modified device tool (it fails to 'see' your device), the most obvious weak link to check is the USB cable itself. Check that it can transfer data as well as power or borrow/buy one that is known to be good. If your PC usually makes a sound when plugging in a USB device and you hear that with the TP, that's a good sign as it suggests some detection, but it might just be a charging connection. A data connection has to then be established for either Dev or USB mode.
1. Turn off your Touchpad.
2. Hold the Vol+ and Power buttons at same time on your TouchPad until the big USB logo is displayed
- The Vol+ button is on the left when you hold the Touchpad horizontally.
3. Plug in your TouchPad to your computer with the USB cable
4. Open up a command prompt (It's a black window)
- On Windows 8 it's an App that says Command Prompt
- Windows 7 How To Open Command Prompt in Windows 7 [Easy, 1 Min]
or Open a Command Prompt window
5. Next, you'll be typing a code to execute the devicetool file you downloaded & modified already.