A few more:
MingW:
http://www.mingw.org/
A Win32 port of the GNU C++ compiler. Can't beat the price of free for it.
C++ Builder, also free, but the compiler part not the IDE:
http://www.borland.com/bcppbuilder/freecompiler/
If you do not mind DOS apps, while at Borland check out the Museum for Turbo C++ 1.01:
http://community.borland.com/museum/
Both links require you to register a free account at Borland.
DJGPP is another free C++ compiler:
http://www.delorie.com/djgpp/
Here is a list of links to free C++ compilers:
http://www.thefreecountry.com/compilers/cpp.shtml
Take your pick of them, enjoy and good luck!