When Discord sits on the connecting screen, the app is trying to reach Discord's servers and getting no answer. It is usually a network problem, a firewall or antivirus block, a VPN or proxy getting in the way, or a Discord outage, rather than a broken install.
ipconfig /flushdns, then reopen Discord so it resolves Discord's servers fresh.If Discord connects on your phone but not on the PC, the problem is on the PC, so work through the firewall and DNS steps again and try the web version of Discord in a browser as a comparison. If no device connects, check the status page again and try a different network, such as a mobile hotspot, to see whether your home network is the problem.
Is Discord down when it is stuck on connecting? Sometimes. A stuck connecting screen is one of the signs of an outage, which is why checking the status page is the first step. If the status page is green, the problem is on your side.
Why does Discord get stuck but other apps work? Discord uses its own servers and connection path, so a block that only affects Discord, such as a firewall rule or a DNS failure for Discord's domains, leaves everything else working.
Does reinstalling Discord delete my messages? No. Messages, servers, and friends live on Discord's servers, not on your PC, so a fresh install signs you back into the same account with everything intact.