QUESTION :
Everyday, the first time I start Safari, if I go to the history tab, I get the following message :
How can I stop Safari prompting this message and completely disable the webpages preview?
ANSWER :
Perhaps you could wipe out the preferences in ~/Library/Preferences/com.apple.Safari.plist and/or clear out the ~/Library/Safari folders and re-open Safari. I’d backup your bookmarks before trying the latter.
Have you tried setting the preferences to “Empty Page”?
I’m now a Mac pro but I searched a bit and found this:
http://roderick.dk/blog/2009/08/03/disable-webpage-preview-images-in-safari-4-final/
Hope this will help!
Try clicking “Add previews now” to prevent the dialog from showing up in the future, and THEN follow the steps mentioned in @r0ca’s link—making sure Safari is not running as you’re doing so, since it’d likely overwrite those preferences when it quits.