this has been discussed so many times - it a bad idea.
REASON - the integration work will all fall apart likely -
Its SIMPLE to install all the parts separately - yes, it requires work - BUT LESS THAN FIXING EVERYTHING THAT GOES WRONG
Every time we get this question, its really for the same reason - the person that seeks the advice is using XAMPP because they don't know how all the pieces fit together. You know the old adage - "if you have to ask the price, you can't afford it"? That's the case here. Its a major task to get all the configurations right. I am not someone who knows everything. I'm learning all the time - I learned all this stuff before coming to XAMPP by having my own 'real servers' (Linux and Windows) and getting IIS, Apache, PHP, MySQL, FileZilla, Webmin, Perl, Hmail, phpMyAdmin (and now python) and a gazillion other parts to work, while learning about the intricacies of permissions, and two major-league different Operating Systems.
As for the PHP downgrade - We just went this about a week ago
read this topic - and learn what he did, find out what and why - and find a link to 'how to do all that" - install separately.viewtopic.php?f=16&t=40499
OR Don't listen to me, Altrea or Nobbie (or that guy) - and go for it. If you do make it work, you will have learned a great deal - but spent a lot of extra time OR it may also just never work right, if at all.