Apache and MySQL not working

[dennylin93]

After I installed XAMPP, I could use Apache, php, MySQL, but after I rebooted my computer, Apache and MySQL stopped working. How can I fix this?
I tried restarting MySQL and Apache, but it didn't work. When I restarted Apache, this message popped up:
NET HELPMSG 3547

[dennylin93]

Never mind. I reinstalled it, and now it works.