How can I pin a CHM file to the taskbar?

"YES!! Absolutely you can. In fact, you can pin any type of document. Here's how:

Find the program you want the file to open with, and create a shortcut to it. In this case, create a shortcut to your %WINDIR%\hh.exe file.
Right-click the shortcut and choose ""Properties...""
In the ""Target:"" box, add your filename to the end inside double quotes, and hit OK.
Right-Click >> Pin to Taskbar and ENJOY!

Here's an example that links to the PHP Manual I have stored in My Documents:
In the ""Target:"" box:
%WINDIR%\hh.exe ""%USERPROFILE%\My Documents\php_manual_en.chm"""

"I came here because I too could not get a CHM to pin to the Win7 taskbar. None of the above suggestions worked for me, but I kept trying, even writing a program that would pin and all it did was open the CHM file. While doing that, I discovered that if the name of my program included the word 'HELP’ Win7 refused to allow pinning.

With that in mind, I renamed the shortcut for a CHM that would not pin to NOT contain the word ‘help’, and now it pins easily, and even with the good old’ drag and drop method!

Just to be clear, the ‘Target’ line of my pinned shortcut is C:\Program Files\AutoIt3\AutoIt.chm (a direct call to the CHM). The name of the shortcut is ‘AutoIt3 H_e_l_p’.

In summary, the ONLY thing that needs to be done out of the ordinary to pin a CHM is to NOT use the word HELP in the shortcut filename."