I am no pro but I think WAMP installs everything into c:\wamp rather than \program files\mysql, \program files\apache\ and so on.
I am a fairly new user so could be totally wrong but I have installed WAMP and did not find any traces of Apache, MySQL or PHP (AMP) outside the c:\wamp\ directory.
If you can and like your system and OS to stay the way it was and try out WAMP you could download Macrium Reflect Free and make an image of your OS.
So to speak the C partition and there only the space that is taken by your current OS installation (Refelect does this automatically, just click "Create an image of the partitions needed to restore the Operating System"
.
Save that image to an external drive or to another partition where you do not have your OS on.
Then you can try out WAMP and if things are fine, fine, but if you find it interferes with your current installations of the AMP stack you can quickly go back to your old OS state and restore the image you made and it will be just like you never had WAMP on your OS partition.
I do this regularly when I install new software.
Best way to keep the registry and OS clean and running I find.
Hope this help.
On another note:
Does it really have to be Joomla? Are you sure about that choice? Since I am curious it would be great to hear why you opt for Joomla. Never tried it so don't know much about it, just heard they often have updates to patch security issues and such. If there is a "must be Joomla" reason for it, I'd love to hear it. I started using WordPress for backend combined with Bootstrap for frontend but might also give Foundation by Zurb a try since that claims to be "the most semantic" framework and Bootstrap clearly isn't very semantic.
Version of Operating system? Windows 7 Ultimate 64bit
Version of Wamp Server installed? 2.5 32bit
Version of Apache you are running? 2.4.9
Version of MySQL you are running? 5.6.17
Version of PHP you are running? 5.5.12
What colour is your WampManager icon? Green
Host file localhost 127.0.0.1
New to WAMP?
Read this please: [
forum.wampserver.com]