Yes - definitely. After some experimentation - and with careful changes to path environment - checking that path has been reloaded prior to running perl - I have found: v5.12.0 will work. v5.12.3 won't work. In both cases I am reasonably confident that there is only one perl.exe on the path at any one time. In both cases 'system' does work correctly with the same parameters as given to 'exec'. I am not saying there is a bug - just commenting on my experience in my installation. Thanks, Ross.