Having multiple previous versions of the game installed has never been supported by Blizzard. One is supposed to run the current version of WC3, plus eventually the PTR version. This is why I personally suggest to install and run any previous versions of the game from inside VMs, to keep things clean.
Error Code BLZBNTBNU00000006 typically occurs when the application being installed was already uninstalled. Please have a look here for possible solutions:
BLZBNTBNU00000006 - Blizzard Support
Should you want to try again to install the current version of WC3, then please use its
official online Blizzard installer for Windows. After that, please try to launch the game with the
-graphicsapi Direct3D9 command line argument, because your Intel GMA 3100 graphics chipset does not support Direct3D 11.
I see your Windows 7 computer has 2GB RAM. I am trusting that at least 256MB is used for the Intel GMA 3100, as shared memory?
In the future, your current computer may become more and more borderline for running the latest version of the game:
Warcraft III System Requirements - Blizzard Support