Sorry to hear about these challenges with the wifi. We’ve seen problems with the wifi gui as well, and we’re working to correct them with a new image build in the next few weeks.
So if you’ve got this setup as a desktop, here are some changes to make to get running:
On your first post, you have a screenshot of /etc/network/interfaces. Did you change the SSID and the PSK to match your network settings? Also, you need your Subnet mask and you gateway to match those of your network. You can get your network settings easily: using a computer that’s already connected to the wifi network you want to join, open windows Command Prompt, and run “ipconfig”. If you’re connected to the network you want to connect your Raspberry Pi to, copy those settings over to your /etc/network/interfaces file.
To choose a static IP address, guess an appropriate number you want your raspberry pi to connect using. Test that number (make sure another device on the network isn’t using that number) by pinging it in the windows command prompt, again on a computer that’s connected to the network you want to connect to “ping 192.168.1.2” or whatever the IP address is that you want to assign. If the ping fails, the number isn’t being used on the network. If you get a ping response, try another valid ip number until you find one that’s not being used. Then change to that number on the address line of the interfaces file.
Since we’re assigning a static ip to the raspberry pi, DHCP should not matter. One problem with a network might be that it requires some validation or assignment from the router. Do new devices, when connecting to the network you’re using, need to be validated through the router admin? Or can you just type in the SSID and PSK to a phone or other device you’re using on the network, and join (no changes to the router)?
In your second post, you say that running “ifconfig” does show eth0 bute not wlan0. Is the wifi dongle plugged in when you don’t see wlan0?
Also, for what it’s worth, I’ve found it’s easier for some reason to use the wifi dongle on the bottom USB port. I don’t know why, but for some reasons wifi dongles sometimes SEEM to fail when plugged into the top USB port. Can you try switching the USB port as well?