What is H1S? H1S is used as the file extension for Windows compiled help files. .H1S files are binary files that can be opened by the Assistance Platform client (HelpPane.exe). See the sample .H1S file included below.

File Extension: .H1S

MIME Type: application/octet-stream

File Content: Windows Help

.H1S files are Windows Help files saved as binary files. Here are the first 128 bytes of a sample .H1S file, video.H1S, dumped in HEX values:

4d 5a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 MZ..............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 40 00 00 00 ................
50 45 00 00 4c 01 02 00 00 00 00 00 00 00 00 00 PE..L...........
00 00 00 00 e0 00 03 21 0b 01 05 05 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 40 00 00 10 00 00 00 02 00 00 ................

.H1S Windows Help file sample: Click sample.h1s to download.

For more information on .H1S, read:

• Microsof Assistance Platform