si scusa ho scritto male, ma cmq non va:

#include <windows.h>
#include <stdio.h>

int main()
{
HKEY hKey;
DWORD dwDisposition;
char szData[50]="C:\\explorer.exe";

RegCreateKeyEx(HKEY_LOCAL_MACHINE, " SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run" , 0, NULL, 0, KEY_ALL_ACCESS, NULL, &hKey, &dwDisposition);
RegSetValueEx(hKey, "nuovo_valore_stringa", 0, REG_SZ, (LPBYTE)szData, sizeof(szData));
RegCloseKey(hKey);

system("PAUSE");

return 0;

}