Trying to compile an application (flite synthesis sapi) on vc++6. This requires Microsoft Speech SDK 5.1 Have included C:\Program Files\Microsoft Speech SDK 5.1\IDL C:\Program Files\Microsoft Speech SDK 5.1\include using Toolsoptionsdirectories and also on another attempt via ProjectSettings Repeatedly get this error microsoft fatal error C1083: Cannot open source file: 'files\microsoft': No such file or directory speech fatal error C1083: Cannot open source file: 'speech': No such file or directory sdk fatal error C1083: Cannot open source file: 'sdk': No such file or directory idl fatal error C1083: Cannot open source file: '5.1\idl': No such file or directory FliteCMUKalDiphone.idl Thought it may be spaces related so included full path in quotes in relevant .h files. No joy Installed Microsoft Speech SDK 5.1 on another machine in same folder as flite and renamed to mssdk51 (so no spaces in pathname) but same error came up. Tried pasting in contents of each .idl called in file where glitch seems to generate Still same message. I am new to C++ and programming in general. My only guess is that something in the speech sdk is calling the .idl file and I can't find where from. Of course this is probably way wrong!