You are facing a winbuilder bug with a bad syntax, I am sure bad syntax come after some trials, but you could not figure out bug and how to workaround ...for your case here it isIf,%SourceArch%,Equal,x64,If,%TargetWOW64%,Equal,x86,FileCopy,%ProjectTemp%\TempExtractFolder\%ProgramFolder%\%ProgramFolder%\IoWrapper.dll,%Target_Win%\SysWOW64Tip: %TargetWOW64% = x86 says there is wow64 exists, if wow64 not exists on a project (future Win9SE ;)), there wouldn't be SysWOW64 , 32bit IoWrapper.dll at SysWOW64 would be meaningless ...... (ex: waik pe)