I download some files, but I can not open to read them because these files use .chm format. How do I can open .chm format files to read ?
My pc use Win XP and Adobe reader 6.0, but these can not open .chm files.

Well this is what I found:
Many new programs are using Microsoft's HTML-based help system, for which the help file extension is .CHM ("compiled HTML file").From: http://www.cambridgesoft.com/services/answers.cfm?PRID=166&FID=2&OS=1
Next time try to search google or another search engine before posting.
Here is a link to a freeware program that you can use to extract the files hope it helps
http://www.gridinsoft.com/chm.php
CHM files should open automatically using C:\Windows\hh.exe Make sure hh.exe is not missing. You can also right-click a CHM file and try to "Open With" that program.
alpha314, Go into your Control Panel and open Folder Options, under the File Types tab hilite CHM and what does it show for "Opens with". The default should be Microsoft HTML Help EXE. If yours shows something else click the Change button and choose Microsoft HTML Help Executable. If that doesn't appear click the Browse button and browse to your C:\Windows folder and choose hh.exe Tufenuf
alpha314, Another easy way to correct the .chm file association would be to go to the link below and download the "CHM File Association Fix" which is a zip file. Download the ZIP and open it. Extract the REG file to your hard disk and double click it. Answer yes to the import prompt. It should restore the default associations for CHM files. Tufenuf
