I used to have Chessmaster 9000 and I can't play it anymore because Direct2Drive was bought out by Gamefly, and they no longer support it! I need something that is versatile and can teach, train and challenge.

Any thoughts?

Download SCID (free database program).  Go to tools and start an engine.

Get the free GUI "Arena" and hook it up to Rybka or Houdini (should be free as well).

What you need is a GUI and an engine.  Here's a link that mentions the differences between the two:

http://www.chessbase.com/support/support.asp?pid=213

WinBoard is my choice for a GUI.  Other choices include Scid, Scid Vs. Pc, Tarrasch, Arena, Kvetka, BabasChess, ChessBaseLight...  There are many, many more.  All of the ones mentioned above are free.  There are also commercial GUIs like Shredder, Fritz, etc.

You also need a chess engine.  Stockfish, Critter, Houdini, and many, many more are all free chess engines that will work will all of the above mentioned GUIs, and all of these are stronger than the engine in Chessmaster.

A few links:

Chess Engine Rating List:  http://computerchess.org.uk/ccrl/404/

Scid Vs. PC:  http://scidvspc.sourceforge.net/

What's new with WinBoard 4.60: http://www.gnu.org/software/xboard/whats_new/4.6.0/index.html

Great, thanks for the replies everyone! I picked up the Arena GUI and found a good free engine called Crafty, although I am unsure how to install/link the Engine with the GUI. The website has minimal info and there is no read me file. Is it just a copy and paste procedure?

In Arena, click ENGINES and then INSTALL NEW ENGINE.

Navigate through your Windows folders and point to the engine EXE.  (With Crafty, it might be Crafty-23.4-win64.exe)

Click Open.

Note that the latest version of Critter, Stockfish, along with Houdini 1.5a, and even Rybka 2.2 are all stronger than Crafty.  (But Crafty is a great engine to have.)

Scid is good, but for what it's worth, I prefer the fork "Scid vs. PC" rather than Scid.

Someone correct me if I'm wrong, but Scid hasn't been updated or worked on in several years.  And yet the author of Scid vs. PC is still working on and maintaining the program.  Scid vs. PC has a lot of improvements over Scid.

"Scid vs. PC (by Steven Atkinson from Australia) began around mid 2009. It was started in response to Scid's poor User Interface and bloated design. Forked from Scid-3.6.26, it has several new features and regular updates from Scid, but is mostly an effort to tidy Shane's frenetic code base, improve the user interface , and add polish to Scid's rich feature set."

Recently, Steven set me up with a custom version that allows me to use my own bitmaps for the board squares.  I'm guessing you will see this feature in the next release.