You could try booting a Linux distro from a USB drive and see how the WiFi card fares under that. Just to confirm that it is in fact not a hardware problem at least.... It would be quicker than doing a reinstallation of an English language version of Windows 7 x64, I would think. I do believe that the AC7260 has Linux drivers available, so that should not be a problem, either.
Also, Is the red X over the icon in the system tray? Because if that is the case, and you say nothing looks bad in Device Manager, it may not be the card per se, but it might just not be connecting due to weak signal. Are you able to set up an ad-hoc network between two devices to see if that works at all? Again, if it does, it is almost surely not a hardware problem.
(BTW, i also have the same NUC/WiFi card combination as you do. I had an issue just the other day where I did have to end up completely uninstalling the Intel WiFi drivers and software, rebooting, and then reinstalling them again, so you might try that too, if you have not already.)
I try to run a file "Setup 188.8.131.52 145 kB". Then it interrupts and I get message, I try to translate it:
Installshield Wizard interrupted
This platform is not compatible with Intel WiDi.
Driver for wireless connection can not find or load the necessary components for Intel WiDi.
Why is it like this?
I have also none a reinstallation, didn't help
Intel® WiDi will not install if your computer does not meet the proper requirements, it will be better to make sure the wireless adapter is working correctly before trying to install Intel® WiDi Software.
Here are the steps required to do a clean install of your wireless adapter software:
- Download and save Intel® PROSet/Wireless Software and Drivers for Windows 7*, version 17.14.0
- Go to Control Panel, Programs and Uninstall Intel® PROSet Wireless Software (if is already installed).
- Go to Control Panel, Device Manager, Network Adapters, right click on the Intel® Dual Band Wireless-AC 7260 and select "Uninstall", make sure to mark the option to "Delete the driver software for this device".
- Reboot the PC, then install the PROSet software 17.14.0 you downloaded before.
If you plan to use Intel® WiDi, it is recommended to update the Intel® HD Graphics Driver for your Intel® NUC, version 184.108.40.20656 can be downloaded at the following location:
Additionally, you may run Intel® WiDi Update Tool, to confirm you system has the required hardware, drivers and software in order to use Intel® WiDi.