A small PowerShell function for unzipping a file.
function fUnzip([string]$sZIPFileName, [string]$sExtractToDir) {
$oShell = new-object -com shell.application
$oZIPFile = $oShell.namespace("$sZIPFileName")
$oExtractTo = $oShell.namespace("$sExtractToDir")
$oExtractTo.Copyhere($oZIPFile.items())
}