感谢大家的帮助 - 我终于设法用这个来终止进程:

Thank you all for your help - I finally managed to kill the process using this:

$output = shell_exec('taskkill /F /IM "uper.exe"');

我相信它也适用于 exec，但重要的是 /F 强制它！:)

I am sure it will work with exec as well, but the important part is the /F forcing it! :)