what are the engines that i can use with winboard

[evergreen1]

I wanted to change the engine. opted for frut2.1 in the start up dailog. i got error message. says
polyglot.pipex_open{}fruit21:the system cannot find the file specified.
what does it mean.

fairymax doesnot allow analysis mode.

what are the engines that i can use with winboard. where can i download them> what are the things i should do before it is being used with winboard?

after playing with an engine, i would like to get analysis of my moves. my each move is critically examined and analysis made. it should say for example--16 a6--it is a bad move since black's bishop is in e8
21.Bf7..... it is not a good move.like that.....

is this happens with engine analysis? if so which engine should i install.