At one of the computers AppServ was used to provide PHP + Apache service from Windows 2008.

Remarks:

No matter, that the host is x64, test first how appserv was installed. If it is 32 bits, then your goal is c:\Windows\SysWow64 instead of System32.

Dependency walker can you hint crazy unsolvable things

Filealyzer will give you no hints.

Blogs will say to copy libelay and ssleay32 dlls to the windows/system32

Consider syswow64

More important: libssh2 is also used by php curl lib, so copy that too.!

So the most important missing item is that without libssh2 curl module will results cannot load php_curl.dll as cannot load module,.

Be aware that DLL hell is coming and will kill you…