This script changes the hint path to a level deeper from http://blog.commandlinekungfu.com/2009/05/not-ready-yet-episode-replacing-strings.html

RecursiveFileStringReplace.ps1

Get-ChildItem -exclude *.bak -Recurse -Include *.csproj | 
	Where-Object {$_.Attributes -ne "Directory"} |     
	ForEach-Object { 
		Copy-Item $_ "$($_).bak"; 
		(Get-Content $_) -replace "<HintPath>..\\..\\Lib","<HintPath>..\\..\\..\\Lib" | Set-Content -path $_ 
	}