The File Extensions Database

.H1S File Extension

  • Developer by: Microsoft
  • Category: System Files
  • Format: Binary

What is an .H1S file?

.H1S is Windows Assistance Platform Help File

Compiled help document format introduced with Windows Vista and also supported in Windows 7; run by the Assistance Platform client (HelpPane.exe), which is installed by default in Windows; used by Microsoft and OEMs for producing help documents, but not used by third-party software developers.

Several pre-installed H1S files can be found in the following directory:


NOTE: H1S files can be compiled using the Apcompnt.exe program included with the Assistance Platform Help Compiler. They can also be decompiled using xHelpMarkup.

Programs that open Windows Assistance Platform Help File
Microsoft Assistance Platform
Help-Info xHelpMarkup

How to solve problems with H1S files

  • Associate the H1S file extension with the correct application. On :
    Windows: Right click on any H1S file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.H1S files". Mac: Right click (or Ctrl-click) the H1S file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .H1S is Windows Assistance Platform Help File. Because only the current version supports the latest H1S file format. Search, therefore, e.g. on the Microsoft manufacturer website after an available .H1S is Windows Assistance Platform Help File update.
  • To make sure that your H1S file is not corrupted or virus-infected, get the file again and scan it with antivirus software.