Failed to create COM object 'X': Class not registered in another WAMP

Question

There already is a working WAMP instance in a Windows 7 in which the line

$x = new COM(\"X\");

does instantiate a COM object.

I was

Answer 1

You need to register the DLL, using

regsvr32 yourdll.dll

Answer 2

Managed to solve the problem by changing the working directory (using chdir) to be the same as the php.exe just before $x = new COM("X");.

I think the DLL wasn't propery registered, or lacked something in itself.