Hi @ll, Microsoft Office 2010 registers the following command lines with unquoted pathnames containing spaces for various supported file types: | C:\> FType | FIND.EXE "=%ProgramFiles%\Microsoft " | | access=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | Access.ACCDAExtension.14=C:\Program Files\Microsoft Office\Office14\MSACCESS.EXE /NOSTARTUP "%1" | Access.Extension.14=C:\Program Files\Microsoft Office\Office14\MSACCESS.EXE /NOSTARTUP "%1" | Access.Shortcut.Query.1=C:\Program Files\Microsoft Office\Office14\MSACCESS.EXE /NOSTARTUP /SHELLSYSTEM [OpenQuery "%1"] | Access.Shortcut.Table.1=C:\Program Files\Microsoft Office\Office14\MSACCESS.EXE /NOSTARTUP /SHELLSYSTEM [OpenTable "%1"] | Access.UriLink.14=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | dqyfile=C:\Program Files\Microsoft Office\Office14\EXCEL.EXE | excel=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | Excel.Chart=C:\Program Files\Microsoft Office\Office14\EXCEL.EXE /dde | Excel.UriLink.14=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | iqyfile=C:\Program Files\Microsoft Office\Office14\EXCEL.EXE /dde | ms-access=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | ms-excel=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | ms-powerpoint=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | ms-publisher=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | ms-word=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | Outlook.File.eml.14=C:\Program Files\Microsoft Office\Office14\OUTLOOK.EXE /eml "%1" | powerpoint=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | PowerPoint.Show.4=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.Show.7=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.Slide.12=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.Slide.4=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.Slide.7=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.Slide.8=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.SlideMacroEnabled.12=C:\Program Files\Microsoft Office\Office14\POWERPNT.EXE "%1" | PowerPoint.UriLink.14=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | publisher=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | Publisher.UriLink.14=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | word=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" | Word.UriLink.14=C:\Program Files\Microsoft Office\Office14\protocolhandler.exe "%1" From <http://msdn.microsoft.com/library/cc144175.aspx> or <http://msdn.microsoft.com/library/cc144101.aspx>: | Note: If any element of the command string contains or might contain ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | spaces, it must be enclosed in quotation marks. Otherwise, if the ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | element contains a space, it will not parse correctly. For instance, | "My Program.exe" starts the application properly. If you use | My Program.exe without quotation marks, then the system attempts to | launch My with Program.exe as its first command line argument. Fortunately these command lines are NOT used when a user opens a file associated with Office 2010 via Windows Explorer: Microsoft Office is installed via "Windows Installer" and lets it create "Darwin descriptors" (see <http://msdn.microsoft.com/en-us/library/aa302344.aspx>). In the presence of a "Darwin descriptor" ShellExecute*() does not use the command line displayed by FType, but queries "Windows Installer" for it. BUT: all program(mer)s who dont use ShellExecute*() but query the registry for the associated command line will execute the rogue programs "C:\Program.exe" or "C:\Program Files\Microsoft.exe" regards Stefan Kanthak