help! windows imagemagick problem!

[designweb]

i install imagemagick in windows,
use convert to resize some pictures in windows's command line.
some image have been reisized,but some image can't and some error happend!
it pop up "imagemagick studio library and utility programs has problem and need to close." alarm window.

why?

thanks!

[designweb]

i find when convert big image file about 200k and more,it will happen problem.
why?
who can resolve this problem.?