apache 2.4 not working on a fresh installed Windows 7 64bits

I am sure this is not a replication issue. I already red about : Apache not starting on windows 7 and XAMPP on Windows - Apache not starting.

But still I haven't found a solution to my concern which seem to be particular.

I am on Windows 7 64bits. It is a fresh installed OS with all important updates made.

I did install xampp 7.x to work on Drupal 7. But apache error "0xc000007b".

After a lot of research I found out that new versions of Apache have a lot of difficulties working on Windows 7.

So I found "XAMPP 1.8.2" (a very old version), binary files that I just donwloaded, uncompressed and place on root drive "c:\". I lauched "XAMPP Control Panel", "Apache" and "MySQL". It worked fine. I could work on Drupal 7.

But now I need to work on Drupal 8 which requires PHP 5.5.9. And PHP 5.5.9 requires APACHE 2.4.

Attempt 1 : New binary files for "apache" and "php"

I upgraded PHP and APACHE (downloading binary PHP and APACHE and replacing folder "php" and overidding folder "apache" on my XAMPP folder). When I launch XAMPP Control Panel, MySQL still works but Apache show this error :

11:42:18 AM [Apache] Port 80 in use by "Unable to open process" with PID 4!

11:42:18 AM [Apache] Apache WILL NOT start without the configured ports free!

11:42:18 AM [Apache] You need to uninstall/disable/reconfigure the blocking application

11:42:18 AM [Apache] or reconfigure Apache and the Control Panel to listen on a different port

11:42:18 AM [Apache] Attempting to start Apache app...

11:42:19 AM [Apache] Status change detected: running

Attempt 2 : Complete new 7.x version install file

When I install a complete new version (with the xampp 7.x install file) such as "7.x", the error message is now : 0c000007b.

How do you think I can solve this issue ?

Thank you a lot.