Hi,
I had this problem on my Linux server (the ImageMagick error in the alfresco.log at startup) so I followed this help page but it isn't complete. On Linux you should change the name of the binary in the [your_tomcat_installation]/webapps/alfresco/WEB-INF/classes/alfresco/content-services-context.xml file and not in the contentServices.xml file as stated in the article.
Some other information is missing here... there are 2 lines you should change in the content-services-context.xml file:
57 <bean name='transformer.ImageMagick.Command' class='org.alfresco.util.exec.RuntimeExec'>
58 <property name='commandMap'>
59 <map>
60 <entry key='Linux'>
61 <value>imconvert ${source} ${options} ${target}</value>
62 </entry>
63 <entry key='*'>
64 <value>imconvert '${source}' ${options} '${target}'</value>
65 </entry>
66 </map>
67 </property>
68 <property name='defaultProperties'>
69 <props>
70 <prop key='options'></prop>
71 </props>
72 </property>
73 </bean>
I can guess why but this isn't documented yet, don't know if this is true for the Windows version as well. More information available in the forum: http://www.alfresco.org/forums/viewtopic.php?t=144&highlight=imconvert
Simon
