I have to second that WhereIsIt? recommendation. In addition to a basic keyword search, there's also an Advanced Search where you can use expressions to specify all kinds of criteria, along with boolean logic like AND, OR, XOR, NOT. WhereIsIt? also has plugins to import metadata and thumbnails for many, many types of files (e.g. image dimensions and EXIF info for images). It even has a basic built-in viewer for images, although it can launch an external viewer of your choice per Windows' file type associations.
You can get WhereIsIt? at
http://www.whereisit-soft.com/.
You might also look at J. River Media Center (
http://jriver.com/), which has a media library with powerful search functionality. Media Center is more of a full-blown home theater application (including a "10-foot interface" mode for use in the living room) than a simple catalog tool, though, but it does work with image files along with everything else.
Neither one of these tools is freeware, though.
Aimhere