To start with, I think this thread should be pinned at least until the cleanup is done.
The two oldest threads (Advanced PHP Resources and MVC Confusion) have been dormant for ten years. I actually remember following them when they were works in progress but they are now completely out of date. I really don't think they provide much value to our typical visitor and are quite misleading.
I don't see much point in the Installing PHP on windows thread either. Most users are going to use something like XAMPP or WAMPP. Those that do want to install from scratch will follow the latest guidelines.
I vote we just unpin those three threads as a start. The other old one are probably not of much use either but I have not looked at them yet.