which edition of windows 32 or 64 bit are supported by macbook pro late 2011

Both. But there is no reason to install the 32 bit version.

1. Your computer is 64 bit
2. New programs are 64 bit
3. 32 bit programs work with 64 bit Windows
4. 32 bit Windows can only address about 3.5GB of RAM so if you currently or plan on having more than 3.5GB RAM you must install 64 bit Windows in order to use all your RAM.

I would go so far as to say there is no reason or need for there to even be 32-bit version.

64-bit has better memory and graphic handling with whatever you have.

http://www.amazon.com/s/ref=nb_sb_ss_c_1_16?url=search-alias%3Dsoftware&field-ke ywords=windows+7+system+builder&sprefix=windows+7+system%2Caps%2C201

Some old programs are only compatible with XP SP1 and SP2, hence they are only compatible with XP 32-bit.

zeephyyr wrote:

Some old programs are only compatible with XP SP1 and SP2, hence they are only compatible with XP 32-bit.

Not true, 64 bit editions of Win 7 and Vista run 32 bit programs with no issues.