Install KeyCAPTCHA on XenForo

1. Download and unzip the archive with KeyCAPTCHA plugin for XenForo 1.x.
2. Copy files KeyCaptcha.php and kc-gettime.php into "library/XenForo/Captcha" directory of your XenForo.
3. Open the control panel of your xenForo (default YOUR_DOMAIN/admin.php).
4. Choose "Add-ons" -> "Install Add-on" from the left menu.
5. Choose the file KeyCAPTCHA-AddOn.xml in "Install from uploaded file" field.
6. Press "Install Add-on" button.
7. Choose "Options" -> "Options" from the left menu.
8. Choose "User Registration" from Option Groups.
9. Switch radio-button "Enable CAPTCHA for Guests" to "Use KeyCAPTCHA".
10. Copy to Сlipboard your private key and paste it to "KeyCAPTCHA Private Key" field.
11. Save all changes ("Save Changes" button is at the bottom of the page).
12. If you are using default "Contact Us" form please complete the steps 13-18. :me
13. Choose "Appearance" from the top menu.
14. Choose "Styles & Templates" -> "Templates" from the left menu.
15. Find and click on "footer" template.
16. Find a line contains "{xen:link 'misc/contact'}".
17. And delete "class="OverlayTrigger" data-overlayOptions="{"fixed":false}"" from this line.
18. Click "Save and Exit" button.
19. If you would like to protect "Lost Password" form please complete the steps 20-31.
20. Choose "Appearance" from the top menu.
21. Choose "Styles & Templates" -> "Templates" from the left menu.
22. Find and click on "login_bar_form" template.
23. Find lines contain "{xen:link lost-password}".
24. And delete "class="OverlayTrigger OverlayCloser"" from these lines.
25. Click "Save and Exit" button.
26. Repeat steps 20-25 for "helper_login_form" template.
27. Choose "Home" from the top menu.
28. Choose "Options" -> "Options" from the left menu.
29. Choose "User Options" from Option Groups.
30. Check the box "Use CAPTCHA for Lost Password Form".
31. Click "Save Changes" button.