Underlined my questions to make them stand out among my babble...LOL

Will IIS 5.1 using Windows XP Pro SP2 OS work best for learning and testing modern PHP "offline" or should I go with latest Apache?
I have never never installed/configured microsofts IIS before, and in the past used Apache because its free. I came across a website about SETTING up IIS 5.1 using oem Windows XP Pro disc and was surprised that its basically free if you already have XP Pro which I do. But before installing and configuring IIS 5.1, I am concerned that it might not have modern handles for modern PHP routines.

Do I have to worry about a mismatch using an older IIS 5.1 with modern PHP or will IIS 5.1 work with all PHP 5.4.9 instructions?
In the past I have used Apache for serving up webpages/sites on private web servers, and when it comes to HTML and Apache its dirt simple to set up. But when trying to get perl_mod working etc it was nothing but headaches for me, and not as simple as removing the # to enable, and even following instructions online something still wasnt right because HTML worked, but perl wouldn't function so something was missing.

So reading online with many others having ISSUES with Apache and trying to ger perl and PHP modules working, I am thinking maybe I should avoid Apache and use IIS for PHP which I will be learning hands on in my free TIME on a spare computer.

http://www.wikihow.com/Configure-IIS-for-Windows-XP-Pro This site makes it sound dirt simple to get IIS 5.1 working in 23 steps. I think its funny that all this time I thought IIS was only available in MS Server Products, as for the last time I came across it but didn't use it was Windows 2000 Server. 

If I should use latest Apache instead, is there any step by step instructions that work with modern Apache to get the perl and PHP modules functioning? I have come across many older ones, and when you try to use the older instructions with mismatched more modern version httpd.conf file instructions, it leads to no perl_mod functionality because the instructions are wrong for newer Apache configuration. ( Mentioning perl here only because I had issues with Apache and perl in the past, and assume that it will be just as much of a problem with PHP.) It's too bad there is no wizard or configuration interface for Apache to help you enable features. A configuration interface should be dirt simple since the httpd.conf file is basically a simple text file. Maybe I should make a Free use Apache Configuration Tool in C++ that makes a custom httpd.conf file that "works" when you want certain modules enabled. LOL  But the only way to do that is to know how to successfully get the modules to work in the first place and with Apache its been nothing but frustration. 

Hopefully this is the correct place for this as for it touches on Programming, Windows XP, and I thought more strongly fit in with Web Design System Configuration, for learning dynamic web design techniques which I am very interested in.PHP works best, IMO, on the LAMP stack. IIS is more for ASP/ASP.NET. Apache on Windows is a bit of a gray area, IMO it works best on Linux, though.

IIS doesn't support PHP out of the box, either. You can find information on getting it setup in both IIS 5.1 as well as 6.0 here.

The same site has instructions for getting PHP working with Apache on Windows as well as Apache on Linux.I use XAMPP and it works pretty well, it sets most of it up automatically and everything is (by default) contained in the C:\xampp directory, with public files in C:\xampp\htdocs\. For basic php+mysql authoring and testing it works pretty well, but for more advanced stuff you'd probably want a dedicated server.In the past months i have been rather fond of EasyPHP... 
http://www.easyphp.org/Thanks Waffle .... I actually ended up not going the route with IIS because it wasnt working as easy as the setups online stated IIS would be with PHP.

I ended up installing EasyPHP about a week ago, but it didnt work at the get go on Windows XP Pro SP2. I installed it and it was broken due to dependencies that were not met by clean build XP Pro SP2. Kept getting errors at start up of services for Apache and mySQL. Searched Google to see what these errors were since it doesnt tell you its Apache or mySQL. Found others with same problems that stated try this/try that. Some stuff I tried didnt CHANGE the issue, but other things did.

In the end I found out that Apache that is bundled with EasyPHP has VC9 dependencies that were not met. So I had to install the redistributable C++ package. I also had to install .Net 3.5 Framework as well as Windows Redistributable Installer 3.1 as linked here: http://www.microsoft.com/en-us/download/details.aspx?id=25 to make EasyPHP run properly, and the Windows Installer 3.1 Redist had to be run prior to the .Net3.5 framework install if my memory is correct.

*If I had connected this system to the internet and performed 100+ updates and brought it forward to Windows XP Pro SP3, EasyPHP probably would have installed without any issues, or only issue being the VC9 redist for Apache.

But this is an OFFLINE Pentium 4 2.0Ghz with 1GB Ram eMachine (motherboard) computer and so I dont need it patched to latest and it actually runs faster at clean build Windows XP Pro SP2 fresh from CD install vs patched in which lesser Ram is available and it seems LESS efficient in operation (there is a performance hit that is noticable... slows down at latest SP3 and all patches )