Windows phot gallery out of memory

Hi When trying to view a photo from the thumbnail, in full, get a message
"this picture cant be displayed, you may not have enough memory available .
close some programs or , if you hard disk is full free some space and try
again"
4 gig of memory two 320gig hard drives plenty of room on them, nothing
really running, tried all the help in the discussions group I can find, no
change. tried various changes in the paging file. any ideas. windows vista
64bit running.