Error updating appinit dlls in the registry
The only thing I did yesterday was to install a game through Steam and now I can't use like 70% of the software on my PC (most of them get this error on the entire program and some only on certain modules of it). If a DLL requires to be loaded at a fixed address(in process virtual address space), but the requirement cannot be fulfilled, Windows asserts the very 0x C0000018 error.
Users reported it happening when they were trying to load Windows Explorer or the Command Prompt, the archiving software 7-Zip, or Mc Afee Data Loss Prevention Endpoint.
A simple Google search of "0x C0000018" just pops you with lots of posts of baffled users.
To reproduce, you can prepare a solution(Visual Studio term) with one EXE and two DLL, and set both DLL to have linker option in the registry is your first bet to get rid of the possible culprits.
I have received the error message "the application was unable to start correctly (0xc0000018)" twice already ever since I upgraded one of my machines to Microsoft's new operating system Windows 10.
A double-click on the application icon in the taskbar does not start the linked program at all but throws the error message instead.