from what i found googling "htmllayout.dll" is part of a virus.
but if you are sure its legit try registering the dll
click start type regsvr32 "the path to the .dll and the name"
examples of places were it is found (i can tell from the path that most of these are were a fake antiviurs would keep them)
%ProgramFiles%\antiviruspro_2010\htmlayout.dll
%ProgramFiles%\antivirusxp2008\htmlayout.dll
%ProgramFiles%\device doctor\1.0.0.1\htmlayout.dll
%ProgramFiles%\eadwareremoval\htmlayout.dll
%ProgramFiles%\e-zsoft\dvdtopspconverter\htmlayout.dll
%ProgramFiles%\e-zsoft\youtubedownloader\htmlayout.dll
%ProgramFiles%\ipod to computer transfer\htmlayout.dll
%ProgramFiles%\macroav\htmlayout.dll
%ProgramFiles%\malware doctor\htmlayout.dll
%ProgramFiles%\smarthide\htmlayout.dll
%ProgramFiles%\versalsoft\internetdownload\htmlayout.dll
%Temp%\antiviruspro_2010\htmlayout.dll
%Temp%\htmlayout.dll