Windows laptop can't find T-Mobile Home Internet network... but all other devices can

NC1037

Well guess what, plugged the USB adapters in and both computers instantly recognized the T Mobile Gateway in both the 5Gig & 2.4Gig bands. Hate to have to buy the adapters but for a non computer literate its the far less frustrating option. Again thanks for all your help.

@syaoran WEP is very old and less secure than WPA.  It's not an option on my gateway. 
TKIP & AES is the only option with WPA/WPA2. 
I agree that AES only is best, and is the only option with WPA2/WPA3 or WPA2.
I don't think not using auto channel selection is an option with my gateway.  Where do you see it?
other than the time I spend here in the forum, I spend less time fiddling with TMHI than I did with my 802.11ac router and spectrum modem or their predecessors.  I remember trial and error with channel selection on my 802.11n routers.  

Don't use auto for channels and always select AES, not AES and TKIP.  Channels 3, 6, and 9 are the most compatible for troubleshooting.  AES as well instead of TKIP or both.  WPA/WPA2 is usually enough for most devices but being a decade old...  WEP is a possibility for as high as the device might support when connecting.  I have am old color laser printer that uses WEP at best when connecting to 2.4GHz WiFi.  If you can, wire the device if the troubleshooting doesn't get it connected, if possible.

Dedicated 2.4 GHz network.  (second network).  It is Hidden because it is less secure than the primary default network.  It is easier to establish initial connection if it is not hidden. (Change to Hidden later)

Here is what the default network looks like in T-Mobile Internet app.  I changed the network name and password; the rest of the configuration is as it came a year ago.  Most devices should be able to connect to this.  The next post will be the dedicated 2.4 GHz network.  
 

The support people don’t have hands-on experience; they work from scripts.  

Since your USB Wi-Fi adapter is due in today, I'll wait to see if that works for you.  If you would like, I can make screenshots of how to connect with Windows 11 and also Windows 10.

In the meantime, here's what my THMI network looks like on my 12-year-old Dell desktop computer (Windows 10).  The driver is from Microsoft and is dated 2013.  (This is just proof that it can work.)

Nc1037

First let me say thank u so much for trying to help me. No I haven't tried any those. I'm an 81 year old neophyte when it comes to computers and how they should work. I can move around win 10 ok but I just got the win 11 unit in so the os is completely new to me. I was able to watch a you tube Video on how to boot the computer without Wi-Fi but have been stuck ever since just trying my win 10 to connect to the TMobile gateway, which I have had to work on an ethernet cable for over a year while trying to get someone at TMobile to help. All they tell me, in the end, is to call the mfg of my computer. Dell tells me the computer is past its lifetime expectancy so they can't help.. Sorry to rant but I'm quite frustrated with the whole TMobile thing, they know they have an issue with pc's so why don't they fix it. My USB Wi-Fi adapter is due in today so I'll try that next then determine weather to stay with Tmobile or move to Spectrum. Thanks again for your help, have to run to a DR appt. now !

@Chaz7138 you shouldn't need a new wi-fi adapter.  Have you tried the others tips in this discussion, such as checking for driver updates, and your Services settings?  I can try to get images from my ancient Dell desktop.

Try setting the 2.5GHz security to WEP, if that is an option to see if that works.

nc1037

Well i set up a new 2.4GH network but computers still wont connect. on the win 10 unit the "manage network screen shows both the 5G & 2.4G networks, however when I switch "show available networks neither shows up. on the win 11 unit doesn''t show either.  I ordered 2 USB 5.0 WIFI adapters today which support both 5G & 2.4G.Hopefully they will work.

Thanks again for your help!!!