How can I remove ReSharper from Windows applications list after the corresponding Visual Studio was uninstalled

Please do the following

1. Open %LocalAppData%\JetBrains\Installations\ folder and remove all the subfolders which names start with ReSharperPlatformVs14 (for Visual Studio 2015), ReSharperPlatformVs15 (for Visual Studio 2017), ReSharperPlatformVs16 (for Visual Studio 2019);
2. Then open "Programs and Features" applet in Control Panel  (not the modern "Add or Remove Programs"). Control Panel can be found at Start | Windows System | Control Panel;
3. Click uninstall for the ReSharper Ultimate record;
4. Windows will notify you that there is no uninstaller and will suggest removing the record.

Pro tip: you may free up the disk space by removing R# caches from the Visual Studio versions you don't use anymore: remove %LocalAppData%\JetBrains\Transient\ReSharperPlatformVs14 (ReSharperPlatformVs15 / ReSharperPlatformVs16 depending on your VS version);