Ошибка преобразования 'char [10]' в 'LPCWSTR'

////////////////////////////
//KWnd.h
#include <windows.h>
 
class KWnd{
public:
    KWnd(LPCTSTR windowName, HINSTANCE hInst, int cmdShow,
        LRESULT (WINAPI * pWndProc)(HWND, UINT, WPARAM, LPARAM),
        LPCTSTR menuName = NULL,
        int x = CW_USEDEFAULT, int y = 0,
        int width = CW_USEDEFAULT, int height = 0,
        UINT classStyle = CS_HREDRAW|CS_VREDRAW,
        DWORD windowStile = WS_OVERLAPPEDWINDOW,
        HWND hParent = NULL);
    HWND GetHWnd(){return hWnd;}
protected:
    HWND hWnd;
    WNDCLASSEX wc;
};
/////////////////////////////
//KWnd.cpp
#include "KWnd.h"
 
KWnd::KWnd(LPCTSTR windowName,HINSTANCE hInst,int cmdShow,
           LRESULT (WINAPI *pWndProc)(HWND, UINT, WPARAM, LPARAM),
           LPCTSTR menuName, int x, int y, int width, int height,
           UINT classStyle, DWORD windowStyle, HWND hParent)
{
    char szClassName[] = "KWndClass";
 
    wc.cbSize       = sizeof(wc);
    wc.style        = classStyle;
    wc.lpfnWndProc  = pWndProc;
    wc.cbClsExtra   = 0;
    wc.cbWndExtra   = 0;
    wc.hInstance    = hInst;
    wc.hIcon        = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor      = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground= (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = menuName;
    wc.lpszClassName= szClassName;
    wc.hIconSm      = LoadIcon(NULL, IDI_APPLICATION);
 
    //рЕГИСТРИРУЕМ КЛАСС
    if (!RegisterClassEx(&wc)){
        char msg[100] = "Cannot  register class: ";
        strcat(msg, szClassName);
        MessageBox(NULL, msg, "Error", MB_OK);
        return;
    }
 
    //Создаем окно
    hWnd = CreateWindow(szClassName, windowName, windowStyle,
        x, y, width, height, hParent, (HMENU)NULL, hInst, NULL);
    if (!hWnd){
        char text[100] = "Cannot create window";
        strcat(text, windowMenu);
        MessageBox(NULL, text, "Error", MB_OK);
        return;
    }
    
    //Показываем окно
    ShowWindow(hWnd, cmdShow);
}
//////////////////////////////////////////
//Main.cpp
#include <windows.h>
#include "KWnd.h"
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
//===================================================
int WINAPI WinMain(HINSTANCE hInstace, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int
                   nCmdShow)
{
    MSG msg;
    KWnd mainWnd("A Hello2 application", hInstace, nCmdShow, WndProc);
 
    while(GetMessage(&msg, NULL, 0,))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
//====================================================
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hDC;
    PAINTSTRUCT ps;
    RECT rect;
    int userReply;
 
    switch (uMsg)
    {
    case WM_PAINT:
        hDC = BeginPaint(hWnd, &ps);
 
        GetClientRect(hWnd, &rect);
        DrawText(hDC, "Hello, Word!", -1, &rect,
            DT_SINGLELINE|DT_CENTER|DT_VCENTER);
 
        EndPaint(hWnd, &ps);
        break;
 
    case WM_CLOSE:
        userReply = MessageBox(hWnd, "А вы уверены?",
            "", MB_YESNO|MB_ICONQUESTION);
        if(IDYES == userReply)
            DestroyWindow(hWnd);
        break;
 
    case WM_DESTROY:
            PostQuitMessage(0);
            break;
 
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}
////////////////////////////

wchar_t str[] = L"String.";

TCHAR szClassName[] = _T("KWndClass");