You have to start the Wireless Zero Config service in order to return control of the Wireless to the OS and work without the HP Wireless Assistant.
Press Win-R and type
services.msc
and press Enter.
Scroll down in the list to the service titled WLAN AutoConfig and double click. Set Startup Type to Automatic, press Apply, then press Start and then OK.
Now you can use the Windows wireless manager and get rid of the useless trash that is any wireless config utility included by the OEM. This is a pretty common issue. The wireless management apps included by OEMs usually have some wiz-bang feature, but when it comes right to it, they offer nothing substantive beyond the Windows built-in manager.
UPDATE:
Most current OEM Wireless Management apps I've seen give the option to return control of the wireless to the OS on uninstall. Because I'm not 100% sure if yours does, do the following:
- Download the latest HP Wireless Assistant from HP so you have the installer on your computer.
- Uninstall the HP Wireless Assistant.
- Reboot and see if Windows' built-in wireless manager can now see and manage the wireless connection.
UPDATE 2: Final steps
As it seems the previous steps don't fix the issue, it would appear the wireless control in your OS is messed up. As there is no indication this is a hardware issue, even if you're under warranty there is nothing HP would do. So that leaves a clean OS install. It's not fun and it's not friendly, but sometimes it's the final solution. I'm sorry none of the previous solutions worked.