Type conversion error?

Question

C++ / C#

Here is the code, I remember when I had to put L-ki before the lines, and now something new again again

if (!UnregisterClass(L"My Window", hinstance))
  {
  }

Error C2664 "BOOL UnregisterClassA(LPCSTR,HINSTANCE)": Cannot convert argument 1 from "const wchar_t [10]" to "LPCSTR"

Answer 1

Removed L-ku and it worked, although one studio requires L, the other does not seem to