[Bergman]

Trident, i dont know how it works in a local server ... sorry ...

I dont think that you should use http:// or c:

Try something like this:
$cfgGalleryDirWeb = '/forum/gallery/'; // absolute web path to gallery files
$cfgImageDirWeb = '/forum/gallery/images/'; // absolute web path to image dir
$cfgImageDirLocal = '/apache/htdocs/forum/gallery/images/'; //The local path to the image dir
$cfgThumbDirWeb = '/forum/gallery/thumbnails/'; // absolute web path to thumbnails dir
$cfgThumbDirLocal = '/apache/htdocs/forum/gallery/thumbnails/'; // The local path to the thumbnails dir
// Put the forums usernumbers for the OakGallery Admins here (comma separated).
// Like this: '1,2,3,4' - NOT like this: '1, 2, 3' !!!
$cfgAdminList = '2';
$cfgForumDir = '/apache/htdocs/forum/'; // The local path to the forum dir
$cfgGalleryDir = '/apache/htdocs/forum/gallery/'; // The local path to the vGallery dir
$cfgConvert = '/usr/bin/X11/convert'; // Local path to ImageMagick's convert
$cfgComposite = '/usr/bin/X11/composite'; // Local path to ImageMagick's composite