>Windows Vista does not support the HLP format, so I had to convert to CHM.
>I can´t find the solution to the proper installation of HTML Help using Installshield 5.53 and VFP 6.

I'm using InstallShield 2008 with a VFP9 app but as far as I know, CHM files just need to be copied to the root application folder. Then, in your application builder you should be able to specify your help file name with the .CHM extension.