CMD返回ErrorLevel而不运行程序

我正在通过CMD提示符运行Powershell命令，我想在开始运行命令之前先检查是否安装了Powershell。如果powershell不存在，我希望脚本退出，但不显示下面的实际错误。这是我的剧本：

@echo off
setlocal enabledelayedexpansion
:: Check to see if Powershell is installed
powershell.exe -command {"test"} > NUL
if errorlevel 1 (
    echo/Powershell is NOT Installed
    EXIT
) else (
    goto PSI
)

:PSI
powershell Set-ExecutionPolicy RemoteSigned

我遇到的问题是，我将此作为输出：

Powershell is NOT Installed

'powershell.exe' is not recognized as an internal or external command,
operable program or batch file.

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明白了！我不得不使用2>NUL而不是NUL来重定向输出：

:: Check to See if Powershell is Installed
powershell.exe test 2>NUL
    if errorlevel 1 (
        echo/Powershell is NOT Installed
    EXIT
    ) else (
    goto PSI
    )

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实际上，上面的powershell命令也会出错。我必须使用powershell“写入输出''n''2>NUL