This is still an issue today with VC 2005 on WinXP. I think the specific reason systemroot env var must be kept to start a VC 2005 compiled binary (automatically means that binary is SXS aware), the (WinXP but not newer) DLL loader when doing SXS passes string "%SystemRoot%\\WinSxS\\" to RtlExpandEnvironmentStrings_U() inside RtlpAssemblyStorageMapResolutionDefaultCallback. SystemRoot has to be defined or else the SXS code can't find the SXS directory where all the SXS tracked DLLs live. -- bulk88 ~ bulk88 at hotmail.com --- via perlbug: queue: perl5 status: open https://rt.perl.org/Ticket/Display.html?id=126041