I am trying all day to install PHP5 and Apache 2.0 on my desktop, but it just didn't work. I tried all tutorials to try and make them work but it never did. Please If someone has a good one, that 100% guarenteed to work, then please post it back. Thanks!

Try installing an XAMPP version. It includes all you need and more.
Windows XP requires some mods to the php.ini and / or the httpd.conf file.

http://www.apachefriends.org/en/index.html

Basically a one click install of php, mysql, mail server, perl, phpadmin, all the stuff you need.

Dear Hadi You can use PHP/Mysql/Apache software .
But its really hard to config 3 object
you can use Zend.Studio for compile your php soruce and you can use an other software like minixampp .
You can search at google to find minixampp for download

I would also definitely recommend Xammp, just like jlhaslip said. Its really easy to use, there are others like this one such as easyphp, but I still think that Xammp is the best I have found.

I recomend you to download the apserver, is the best server package for the pc. I tried also the xampy but is not so good, it has some problems with the php.

I remember back when i was trying to do the same thing. I've tried WAMP, and others, and they just didn't work out the way i wanted to. So i went out looking at many ways to install these things manually. And after many trials and errors, i finally managed to get it to work the way i want. I also made a tutorial about it. Pretty straightforward, and has some troubleshooting solutions (the kinds i have encountered >_>). Tutorial Link. It may not be for PHP5, but the installation for PHP5 isn't that much different. But you'll get Apache 2 working, and the rest.

farciscript, Flakes, contor and truefusion, thank you all for helping, but I finally managed to install xampp, the problem was that I installed apache alone, and then xampp. So I had to uninstall xampp and apache and just reinstall xampp. The problem is solved thank you all!!