Try the following actions, as they may actually help in this type of situations:
1. Do a clean install of the most current driver.
- Download Intel® PROSet/Wireless Software for Windows 8.1* version 17.16.0.
- Go to Windows Device Manager - Network Adapters, locate the Intel® Dual Band Wireless-AC 7260, right click on it and Uninstall it, make sure to select the option "Delete the driver software for this device"
- Scan for hardware changes or reboot the PC, if another version of the driver is reinstalled, proceed to uninstall and delete it again, until it does not allow removing it anymore.
- Proceed to install the driver 17.16.0 you had downloaded.
2. Apply the configuration from the document:
3. If you are not using Bluetooth, disable the Bluetooth adapter. BT signals may cause interference to WiFi connectivity. This is normally done with a switch in the Computer or from Windows PC settings - PC and Devices menu.
If the issue remains after this, please provide the brand and model of you PC, wireless driver version shown in device manager, model and firmware of your WiFi access point.