Patching Windows Media Player

I’m writing this post on the request of @rudr4_sarkar. This is a very simple patch in which you can open multiple instances of wmplayer. It basically uses the ‘CreateMutexW’ API to create a mutex object with the string “Local\Microsoft_WMP_70_CheckForOtherInstanceMutex”.


The pseudo code would be something like this
[code language=”c”]
HANDLE hMutex = CreateMutex(NULL, FALSE, L"Local\Microsoft_WMP_70_CheckForOtherInstanceMutex");
if (GetLastError() == ERROR_ALREADY_EXISTS) {

You just need to patch the ‘JNZ’ to a ‘JMP’ instruction, that will always jump to the good boy 🙂


You can also do this on runtime by killing the Mutant handle using Process Explorer.


Here’s a small patch which I wrote for fun in C++ fully using the win32 API. I have included 2 versions. The first version works with both Windows 7 and 8, while the the other works with Windows 10.



After patching you should be able to open as many as windows you like and enjoy music and other tasks 🙂

This is strictly written for educational purposes. The author doesn’t take any responsibility for your actions.

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