'ping' 不是內部或外部命令、可執行的程式或批次檔

C:\>path
PATH=C:\Program Files\Common Files\Microsoft Shared\Windows Live;
C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;
C:\Program Files (x86)\IVT Corporation\BlueSoleil\Mobile;
C:\Program Files (x86)\Windows Live\Shared
C:\Windows\System32>ping

使用方式: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]
[-r count] [-s count] [[-j host-list] | [-k host-list]]
[-w timeout] [-R] [-S srcaddr] [-4] [-6] target_name