#9 php_mbstring.dll (2.5.10) not found

[lu_icst]

php_mbstring.dll (2.5.10) not found

on Windows XP or Windows 2003

on "Command Prompt" Mode

C:
cd C:\AppServ\www
C:\AppServ\php5\php.exe C:\AppServ\www\phpinfo.php

It show
This program can not start, because find php_mbstring.dll

But I can use normally on AppServ 2.5.9

If I add "C:\AppServ\php5\ext" to %PATH% Enviroment Variable,
program could run correctly

PS: I am under "Tradition Chinese" Operating System
Chinese Proper nouns that I use may not be translate to the correct English name.