In some platforms, the operating system may incorrectly pass (one of) the quotes of your command line parameters to the utilities tex4ht.exe and t4ht.exe. This occurs under Windows NT, for example, when the quoted argument is a directory name as part of the -d parameter (eg the parameter "-dc:\mydir\" will be seen as -dc:\mydir" with the trailing quote). When this happens, part of Tex4ht will complain and/or the files will not get written to where you intend. The problem can be resolved by by installing the filter named `htcmd', and passing the tex4ht.exe and t4ht.exe commands through the filter. For instance, if htlatex.bat contains a command line of the form `C:\tex4ht\t4ht %1 %4', then you pass this through the htcmd filter by changing the command to 'C:\tex4ht\htcmd C:\\tex4ht\\t4ht %1 %4'. In the specific WinNT problem above, the preferred solution is to always use Unix syntax for directory separators (ie the / character instead of Windows/DOS's \ ), which is consistent with the syntax in the rest of TeX4ht, and then add the -slash switch when you invoke htcmd. So here the line `C:\tex4ht\t4ht %1 %4' would be replaced by `C:\tex4ht\htcmd -slash c:\tex4ht\t4ht %1 %4' and the actual argument you type is "-dc:/mydir/" (with the quotes). If you are using UNC names, then use the -dslash option to have '/' translated to '\\'.