Forum Moderators: coopster
Assuming it's a test server you're talking about and not a live server, simply install as normal - Apache installed automatically in
C:\Program Files (x86)\Apache Software Foundation and PHP in C:\Program Files (x86)\PHP. Note, I prefer to install the components individually and from scratch, so I haven't tried any of the pre-prepared packages out there, but I suspect they will work perfectly as well. You merely have to remember to edit the configuration files in Administrator mode due to UAC. So, in short, it's a non-problem as 64-bit Vista/7's 32-bit compatibility layer is seamless (and 64-bit Vista or 7 is way better than 32-bit XP anyway!). :)
C:\Program Files (x86)\ and have access to 32-bit Windows libraries. There's no reason to go for 32-bit Windows now unless you have to run 16-bit MS-DOS programs (which won't run on 64-bit) or you have a netbook with an Atom processor.
As for Apache, I guess they will catch up with the release of a 64-bit, but for a test server it doesn't matter. For a live server, you would be missing out on the advantages of 64-bit (memory above 4Gb for example), so Apache + Windows 64-bit isn't ready for a production environment.