Some PECL extensions aren't available in the php.net url above. They have to be downloaded from https://pecl.php.net/packages.php. Currently their Windows machine is dead, so some extensions dlls are unavailable, e.g. grpc
PECL extensions are pre-built for Windows and available from: » http://windows.php.net/downloads/pecl/releases/
Some extensions use features specific to some Unix systems and so are not available on Windows. Otherwise, all extensions are available for Windows.
Some PECL extensions aren't available in the php.net url above. They have to be downloaded from https://pecl.php.net/packages.php. Currently their Windows machine is dead, so some extensions dlls are unavailable, e.g. grpc