paperclip plugin not working on windows

the paperclip works on ubuntu but on windows it gives an some error. the error is " There were problems with the following fields: Avatar C:/DOCUME~1/ozone/LOCALS~1/Temp/Water lilies,2700,0.jpg is not recognized by the 'identify' command. Avatar C:/DOCUME~1/ozone/LOCALS~1/Temp/Water lilies,2700,0.jpg is not recognized by the 'identify' command "

any idea ?? i'm almost stuck here

thanks