[Nut-upsuser] Windows driver installer not always successful

[Kris Jordan]

The Windows driver installer isn't always successful, actually most of 
the time it fails. I thought it was due to differences between Windows 
XP and 7 or different UPS models. But I'm noticing that it might be a 
bit more random than that.

What does seem to always work is running wdi-simple.exe from the others 
folder manually.

When having it run from the NUT installer, it will extract usb_driver to 
windows\system32 (or syswow64). And when run afterwards, the others 
folder instead. Not sure if that is really a problem or not except a bit 
messy.

As always, thanks!