WMF/JPEG Thumbnails won't show

I am unable to get my hundreds of pieces of wmf & jpeg clipart pieces to
show as thumbnails, only as a generic program file (Usually Paintbrush).
My previous three computers had no problems with the clipart.
I have:
- Unchecked "always show as icons.."
- Messed with folder options
- Spent 35 minutes on remote assist with Dell- they say Vista sees
these files as some sort of spyware.
- Done the Vista Forum tutorials for turning thumbnails on/off
- Tried changing the registry

I need to be able to quickly see what all the theumbnails are and not
have to click individually.

Any advice would be appreciated.