Hello Everybody:
Just to tell you that i'm finally generating autothumbnails.
This is how I did it...
1 - Forget ImageMagick
Forget ImageMagick. Go for the GD library, which is an extension for php, already included in the instalation.
Edit your php.ini and uncomment the line
extension=php_gd.dll
then restart windows.
if you get an error similar to "unable to load dinamic library php_gd.dll", get a copy of libsasl.dll and put it in the directory that holds php.exe.
restart it again, if needed.
then go to the settings of admin site of 4images and change the library to GD.
now try generating the autothumbnails...
voilá! there you have it...
To Jan:
Just a suggestion Jan, put this hint in the install documentation. It helps a lot. At least, it helped me...