The default install of GalleryRemote on Windows 7 64-bit works, but the client image resizing does not. This is a pain, especially these days with digital pictures that are sometimes over 10 MB. The problem was the ImageMagick library. I found this to work for me:
Install Imagamagick
Pick the Q16-windows-x64-static.exe version of Imagemagick, latest version, from http://www.imagemagick.org/download/binaries/.
Configure convert.exe path
Edit the file imagemagick/im.properties in the GalleryRemote directory, and set the im.convertPath to the DOS 8.3 compatible name of the convert binary, using a forward slash as directory separator (Hint: use dir /x to list the 8.3 names. The result may vary for different versions of ImageMagick; in my case it looked like:
im.convertPath=C:/progra~1/imagem~1.5-q/convert.exe
At this stage the resize did work again.
Update 2012-03-21. Secunia PSI notified me that 6.7.5-1 was vulnerable. I uninstalled that and installed the newer version 6.7.6-1. This means you have to update the configuration to reflect this as well. In my case the path changed to:
im.convertPath=C:/progra~1/imagem~1.6-q/convert.exe