K-lite Codec will update MPC 64-bit IF MPC 64-bit in already installed as part of the K-lite Codec bundle. The MPC 64-bit program is located in the following folder (on a Windows 64 machine):
C:\Program Files (x86)\K-Lite Codec Pack\MPC-HC64\mpc-hc64.exe
In selecting MPC in the "Programs to be Updated" panel, PatchMyPC downloads the 32-bit version of MPC and installs it in a Program Files (x86) folder of its own.
The problem is that there is no option to update MPC 64-bit to the latest version. One must accept the version offered in the K-lite Codec update. The MPC 64-bit version offered as part of the K-lite Codec update is often not the latest version.
If one downloads the latest MPC 64-bit player (.exe) from /https://nightly.mpc-hc.org (https://nightly.mpc-hc.org), the 64-bit program installs correctly in the folder:
C:\Program Files (x86)\K-Lite Codec Pack\MPC-HC64\mpc-hc64.exe
PatchMyPC does not look in this folder for the installed 64-bit MPC program to determine if a newer version is available.
EmmttGlnn2002
PatchMyPC actually installs MPC x64 in "C:\Program Files\MPC-HC"
And installs K-Lite Codec Pack & its MPC x64 in "C:\Program Files (x86)\K-Lite Codec Pack\MPC-HC64"
We just tested and we haven't seen any problems.