Download Glaurung 2.2 you will love this chess engine i run it on Arena 2 an on a Fritz 8 inteface an plan to load it on my other Free uci platforms.On CCRL they have it at 2845 40 in 40 min. however i find it harder to play against than say Rybka 2.2 rated 2988 40 in 40 also another good free chess engine.Until i buy a new computer for now i am limited to the 32 bit single cpu but both support 64 bit an multi cpu hardware,When you download rybka 2.2 rated 2988 an stelka 2b rated 2978 an Toga II 1.4 beta5c rated 2920 or thinker 5.3 rated 2931 by the way these compare well to Fritz 11 32bit single cpu rated 2961.Know what with these type good Free chess engines i think i can wait to the replacement for Vista comes out i will stick to my old 2005 amd win xp.By the way thinkers a win engine so load that one on arena as it supports all  uci or win engines an i use the arena little opening book with all engines on arena 2 to get a fair comparison.

what's so special about Glaurung 2.2 free uci chess engine

Chessmaster is better

i used Arena too is Great cheesboard

Glarung also comes with this interesting free program:

http://innokuo.altervista.org/chesshero.html

I hope Erik adds something like this guess-the-move software to chess.com :-)