niltinho wrote:Is there a way I could upgrade only the Apache itself and not the PHP for the time being?
Honestly, i dont know. The main problem is, that there are certain interface DLLs (phpts.dll or similar) which have to match as well PHP as Apache. I am not sure, if there is a solution for "very old PHP" and "very new Apache". Usually the tools match to each other. Of course, it is possible not to run the very newest PHP with a very new Apache, but i dont know were this kind of compatibility stops. I dont think that you can mix any Apache version with any PHP version.
Anyway, it is a quite a big task to replace Apache in Xampp and it is not recommended to replace any of the tools delivered by Xampp. That is one of the disadvantages of having Xampp, take it as it is or leave it. On the other hand, the advantage of Xampp is the "easy installation" and the properly preconfigured environment.
If I were you, I would try to install Apache/MySQL/PHP standalone, not from Xampp, and choose the versions you need. Then try to configure the whole stuff in order to run properly. That sounds more difficult as it is and i dont think that it might be easier to "simply" replace Apache in an existing Xampp installation. Of course you must backup all your things (including the whole Xampp installation) before any further action. If you can use a different PC for the "new" installation, that would be the safest way not to destroy your existing environment.