Top 10 CHM Book Readers for Windows

CHM Book Readers for Windows allow to open and read CHM books on Windows desktops and tablets
FBReader is an free eBook reader that supports numerous file formats like ePub, fb2, plucker, HTML, plain text, doc and more. You can also add multiple books at once in an archived format (tar, zip, gzip, bzip2). It supports embedded images, footnotes, hyperlinks, text search and full screen reading. It also has automatic bookmarking so that you don’t lose your place when closing a book.
AndroidBlackberrySymbianWindows PCMac OSLinux
CoolReader - an open-source program for reading electronic books in a variety of formats for Windows and Linux. There are also versions for OS Android and e-reading devices (LBook, PocketBook)
AndroidWindows PCLinux
SumatraPDF, also known as Sumatra, is a free and open-source software PDF reader for Microsoft Windows only. The program also opens Open XML Paper Specification, DjVu, EPUB, XPS, CHM, CBZ and CBR, and MOBI files
Windows PC
Okular is a universal book viewer based on KPDF for KDE 4. This means Okular works on multiple platforms, including but not limited to Linux, Windows, Mac OS X, *BSD, etc. Okular combines the excellent functionalities of KPDF with the versatility of supporting different kind of documents, like PDF, Postscript, DjVu, CHM, XPS, ePub and others.
Windows PCMac OSLinux