Question

不小心将环境变量删除了，结果dos 中的“where”,"fc"等命令就用不来了了，请问怎样办？

Answer 1

还有where这个DOS命令？？？

环境变量删除了，可再添加上：
%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;

也可将下面内容保存为.reg文件，再导入：

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment]
"ComSpec"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,63,\
00,6d,00,64,00,2e,00,65,00,78,00,65,00,00,00
"FP_NO_HOST_CHECK"="NO"
"OS"="Windows_NT"
"Path"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,\
00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,3b,00,25,00,\
53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,00,3b,00,25,\
00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,00,5c,00,\
53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,57,00,62,00,65,00,6d,\
00,3b,00,00,00
"PATHEXT"=".COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH"
"TEMP"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,\
00,25,00,5c,00,54,00,45,00,4d,00,50,00,00,00
"TMP"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,\
25,00,5c,00,54,00,45,00,4d,00,50,00,00,00
"windir"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,\
00,25,00,00,00