$debugRegex = 'Debug'
$releaseRegex = 'Release'
$path = 'g:\Projects\'
$f = "*.*proj"

foreach ( $file in gci -Path $path -Filter $f -Recurse) {
	$file.FullName
	foreach($line in [System.IO.File]::ReadLines($file.FullName) | Where-Object {$_ -match $debugRegex})
	{
		if( $line -match $releaseRegex) {
			$line
		}
	}
}