When your desktop/laptop gets connected to the wireless router, it issues a DHCP request to that same router to get its TCP/IP configuration (ip address, gateway ip, dns server(s), etc.). But if for some reason the DHCP server doesn’t respond, the desktop/laptop gives up and assigns itself an ip address in the 169.254.x.x address space, then gives the message "limited or no connectivity" (although it now does have an ip address, for all intents and purposes, it’s useless).
So you need to dig a little deeper and determine why your DHCP server is not responding. Or maybe (if unlikely), your desktop/laptop is not configured to use DHCP. Or, assuming this is your own wireless router, you might try rebooting it, or even setting it back to factory defaults (it might just be a bug, or hung, etc.).