Net start mysql starts mysql and prompts a system error. 5. How can I solve this problem? After some consideration, I found the cause because the current user's operation permission is too low and an error occurs. The screenshot is as follows: running net start mysql in dos cannot start mysql! Prompt system error 5; Access Denied! Switch to administrator mode. Therefore, we need to run the cmd program as an administrator to start mysql. So how can I run the cmd program as an administrator? 1. In the search box of the Start menu, right-click and select Run as administrator! If mysql is to be started every day, isn't it very troublesome? So: 2. right-click cmd and choose "attach to start menu (U)". You can find cmd in the Start Menu. 3. right-click "select Properties", select "shortcut", select "advanced", run as administrator, and click "OK! In the future, you only need to open the Start menu and click the shortcut above to run cmd as an administrator! In this way, the input of net start mysql will not cause errors!