I am running the PECL PHP-Memcached 3.2.0 on PHP 7.x and PHP 8.1.0 Windows servers without problem.
Unfortunately, it's impossible to make it work under PHP 8.1.7.
Unable to load dynamic library - The specified module could not be found
I obviously specify that the DLL extension is in the right directory, and that it is of course the x64 TS VS16 version.
Solution: The two dependencies DLLs (libmemcached.dll and libhashkit.dll) must be copied under c:\windows or in any directory belonging to the %PATH%
Restart your webserver service.