下面的代码，运行中发现，无法比较啊。如何处理？
@echo off
@for /f "tokens=2*" %%i in ('reg query HKLM\SOFTWARE\Clients\Mail /v "" ^| findstr /i /c:"REG_SZ"') do ( set client=%%j)
@msg %username% /time 3 "检测到邮件默认程序:"%client%
@set MO='Microsoft Outlook'
@set HO='Hotmail'
@set WL='Windows Live Mail'
@set WM='Windows Mail'
@set OE='Outlook Express'
:@if '%client%' = %MO% (goto NS)
:@if '%client%' = %HO% (goto NS)
:@if '%client%' = %WL% (goto NS)
:@if '%client%' = %WM% (goto NS)
@if not '%client%' == %OE% (goto NS) else (goto OE)
