Faulty Wireless on old Dell Inspiron Desktop

Dell Wireless 1506.802.11blgh (2.4GHz) reports “This device is working properly” - but it isn’t. Phone, iPad etc have good signal, desktop just shows the “world” symbol with a full “fan” symbol and says “No internet, secured”.

I’ve tried resetting it - no change.

What can I do? Can I buy and fit another adapter?