Here is the method I used to install the Tech2Win software with the VXDIAG Nano device, which worked for me and is provided for your reference:
First, do not connect the device to the computer until everything is fully installed. I used Windows 7 32-bit, as the drivers do not work on 64-bit systems and need to be reinstalled on a 32-bit OS. Make sure Windows 7 Service Pack 1 and Microsoft Visual C++ 2015 Redistributable are installed, as SP1 is a requirement for the C++ package, which in turn is required by the software-otherwise, it will trigger errors about missing .dll files. Disable User Account Control from Control Panel > User Accounts, and allow installation of unsigned drivers using gpedit.msc (you can find detailed steps for this online).
Install Tech2Win (it will show unsigned driver warnings-just accept them), then install VX Manager. Now connect the VCX Nano device to the computer's USB port. Open Tech2Win, select North America, and choose the option based on your vehicle. Wait for initialization to complete, then close the software and restart your computer.
After this process, everything worked exactly as it should. I was able to perform all Tech2 functions on my 2002 Trans-Am.
This is an excellent device and a full replacement for MDI and similar tools.