I had explorer set up to show all folders as 'details', but a few days ago all folders now open in 'icon' view. I have tried to reset using tools>folder options>view -remember each folders view settings. I also followed advice from previous threads and repaired explorer, also I've used system restore to a time way before the problem manifested. None of these remedies has changed the way explorer opens. Antivirus is up to date and run regularly. Spyware, malware and adware scans aslo show a clean system. I'm baffled as to what to try next and would appreciate your help.
I see you've tried all sorts of fixes, I don't know if the following will help. TweakUI XP/Explorer/Customizations, change Folders to Remember to 1 or 0, Apply, reboot, back to the same screen and change back to 5000 or something, reboot again. Perhaps it will clear out that part of the registry. Basically the same registry keys being changed as in the links VoG supplied, you could do the registry edits if you don't have TweakUI on your machine.