你也可以使用.NET来截图（这给了你更好的控制）：

[Reflection.Assembly]::LoadWithPartialName("System.Drawing")
function screenshot([Drawing.Rectangle]$bounds, $path) {
   $bmp = New-Object Drawing.Bitmap $bounds.width, $bounds.height
   $graphics = [Drawing.Graphics]::FromImage($bmp)

   $graphics.CopyFromScreen($bounds.Location, [Drawing.Point]::Empty, $bounds.size)

   $bmp.Save($path)

   $graphics.Dispose()
   $bmp.Dispose()
}

$bounds = [Drawing.Rectangle]::FromLTRB(0, 0, 1000, 900)
screenshot $bounds "C:\screenshot.png"

为了完成，这个脚本允许您在多个监视器上进行屏幕截图。
基本代码来自Jeremy。

function screenshot($path)
{
    [void] [Reflection.Assembly]::LoadWithPartialName("System.Drawing")
    [void] [Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
    $left = [Int32]::MaxValue
    $top = [Int32]::MaxValue
    $right = [Int32]::MinValue
    $bottom = [Int32]::MinValue

    foreach ($screen in [Windows.Forms.Screen]::AllScreens)
    {
        if ($screen.Bounds.X -lt $left)
        {
            $left = $screen.Bounds.X;
        }
        if ($screen.Bounds.Y -lt $top)
        {
            $top = $screen.Bounds.Y;
        }
        if ($screen.Bounds.X + $screen.Bounds.Width -gt $right)
        {
            $right = $screen.Bounds.X + $screen.Bounds.Width;
        }
        if ($screen.Bounds.Y + $screen.Bounds.Height -gt $bottom)
        {
            $bottom = $screen.Bounds.Y + $screen.Bounds.Height;
        }
    }

    $bounds = [Drawing.Rectangle]::FromLTRB($left, $top, $right, $bottom);
    $bmp = New-Object Drawing.Bitmap $bounds.Width, $bounds.Height;
    $graphics = [Drawing.Graphics]::FromImage($bmp);

    $graphics.CopyFromScreen($bounds.Location, [Drawing.Point]::Empty, $bounds.size);

    $bmp.Save($path);

    $graphics.Dispose();
    $bmp.Dispose();
}

它可以被称为：屏幕截图“D：\screenshot.png”

此PowerShell函数将捕获PowerShell中的屏幕并将其保存到自动编号的文件中。如果使用-OfWindow开关，则将捕获当前窗口。
这是通过使用内置的PRINTSCREEN /CTRL-PRINTSCREEN技巧来实现的，它使用位图编码器将文件保存到磁盘。

function Get-ScreenCapture
{
    param(
    [Switch]$OfWindow
    )

    begin {
        Add-Type -AssemblyName System.Drawing
        $jpegCodec = [Drawing.Imaging.ImageCodecInfo]::GetImageEncoders() |
            Where-Object { $_.FormatDescription -eq "JPEG" }
    }
    process {
        Start-Sleep -Milliseconds 250
        if ($OfWindow) {
            [Windows.Forms.Sendkeys]::SendWait("%{PrtSc}")
        } else {
            [Windows.Forms.Sendkeys]::SendWait("{PrtSc}")
        }
        Start-Sleep -Milliseconds 250
        $bitmap = [Windows.Forms.Clipboard]::GetImage()
        $ep = New-Object Drawing.Imaging.EncoderParameters
        $ep.Param[0] = New-Object Drawing.Imaging.EncoderParameter ([System.Drawing.Imaging.Encoder]::Quality, [long]100)
        $screenCapturePathBase = "$pwd\ScreenCapture"
        $c = 0
        while (Test-Path "${screenCapturePathBase}${c}.jpg") {
            $c++
        }
        $bitmap.Save("${screenCapturePathBase}${c}.jpg", $jpegCodec, $ep)
    }
}

这是我的多显示器解决方案，比目前的答案简单一点。如果用户有一个奇怪的显示器配置（垂直堆叠等）没有黑条，它也会正确地呈现屏幕。

Add-Type -AssemblyName System.Windows.Forms,System.Drawing

$screens = [Windows.Forms.Screen]::AllScreens

$top    = ($screens.Bounds.Top    | Measure-Object -Minimum).Minimum
$left   = ($screens.Bounds.Left   | Measure-Object -Minimum).Minimum
$right  = ($screens.Bounds.Right  | Measure-Object -Maximum).Maximum
$bottom = ($screens.Bounds.Bottom | Measure-Object -Maximum).Maximum

$bounds   = [Drawing.Rectangle]::FromLTRB($left, $top, $right, $bottom)
$bmp      = New-Object System.Drawing.Bitmap ([int]$bounds.width), ([int]$bounds.height)
$graphics = [Drawing.Graphics]::FromImage($bmp)

$graphics.CopyFromScreen($bounds.Location, [Drawing.Point]::Empty, $bounds.size)

$bmp.Save("$env:USERPROFILE\test.png")

$graphics.Dispose()
$bmp.Dispose()

Microsoft在这里提供了一个PowerShell脚本：
http://gallery.technet.microsoft.com/scriptcenter/eeff544a-f690-4f6b-a586-11eea6fc5eb8
我刚刚在Windows 7机器上尝试了它，它可以工作，使用提供的命令行示例：

Take-ScreenShot -screen -file "C:\image.png" -imagetype png