mIRC currently supports both the mirc.chm and mirc.hlp files. It will try mirc.chm first and mirc.hlp second. I may remove support for mirc.hlp at some point, I left it in for users who might prefer it. As someone noted, mIRC supported mirc.chm files long before the official mirc.chm was released in 6.21. This was for users who had created their own mirc.chm file from mirc.hlp.
