WLAN key wrong after upgrading from windows 8.1 to windows 10

After upgrading my HP split X2 from Windows 8.1 to Windows 10 I had some problems with the wireless LAN connection. At first the connection was lost after a few minutes and after a while I did not connect any more.

It always said that the provided wireless lan passphrase was wrong.
I tried some things like:

• reinstall wlan drivers (in my case: Ralink RT3290 802.11bgn Wi-Fi Adapter)
• restart router (in my case: Netgear DGND3800B)
• change passphrase of the networ
• Execute "netsh winsock reset catalog" in the command prompt (found that while looking for solutins to this this problem on google)
• .... (many more things)

Nothing of that worked and I already was afraid that I had to reinstall windows. Than I had a closer look imnto the properties of my wirless adapter. There is one option "Adhoc support 802.11n" and after changing that all my problems were gone.

Here again the solution that worked for me step by step:
- type "device manager" into the prompt of the taskbar
- select "device manager"
- look for wireless adapter under "network adapters"
- right-click on wireless adapter
- select "properties"
- select "advanced"
- select "adhoc support 802.11n"
- change value to "activated"
- Save by clicking on "OK"


Update 22.09.2015:
Problem occured again so the steps described before weren't the solution.
Next I tried the following:

- Open device manager
- look for wireless adapter under "network adapters"
- right-click on wireless adapter
- Click on unistall
- Now here there was a checkbox for uninstall the drivers from system. Activate that checkbox and click OK.
- Right click on "network adapters" 
- Select "scan for hardware changes"

After that the driver for the wireless adapter is installed in an old version and that works for me until now.