Windows11 Open with dialog shows apps that are no longer installed on the system

The entries remain because Open with is built from application and file-association registrations, not solely from installed executables. Microsoft documents that applications can register supported file types and Open with verbs in per-user or machine registry locations; an incomplete uninstaller can therefore leave a stale registration. Do not use a registry cleaner. Open Settings > Apps > Default apps, search for the affected extension, and assign the intended application. If you know which removed program created the entry, reinstall it from its publisher and uninstall it normally, then restart Explorer or sign out. Check whether the stale choice appears for one extension or every file type. If it is limited to one extension, collect the extension, displayed application name, and whether the executable still exists. Manual registry removal is possible but unsupported without identifying every related registration. Report the leftover association to the application publisher, whose installer should remove it.