Windows registry entries for default explorer view

There seems to be multiple things that might cause this as an issue, and multiple resolutions as well, hopefully solving or making this "bug" appear less frequently.

1. Manually resetting the folder view cache/settings
   1. Start regedit. (Win+R, enter regedit, press Enter or click OK. )
   2. Browse to HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell.
   3. Delete the keys Bags and BagMRU.
   4. Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell, repeat step 3.
   5. Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam, repeat step 3.

Trying some of these additional tweaks might help, mix it with it and see what you get.

• Disabling automatic folder type discovery
  1. Browse to HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell in regedit.
  2. Create a new key under Shell, called Bags.
  3. Create a new key under Bags, called AllFolders.
  4. Create a new key under AllFolders, called Shell.
  5. Create a new string value under Shell, called FolderType.
  6. Set the string value of FolderType to NotSpecified.

You can increase the size of the folder view cache as well.

• Increasing the size of the folder view cache

  1. Browse to HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell.
  2. Set the DWORD value of BagMRU size to something higher than 5000.
     • Note: If it's not there, create it.

• After resetting the cache/settings + apply tweaks

  1. Log off/on or reboot.
  2. Open a Windows Explorer window and go to the Folder Options window.
     1. Select the View tab.
     2. Check Remember each folder's view settings.
     3. Uncheck Restore previous folder windows at logon.
     4. Hit the OK!

This should do it, or rather, perhaps improve the experience. Nevertheless, using an application as CCleaner with the wrong settings can disrupt and delete your settings, so be aware and checking before you use applications focused on "cleaning up".

How frequently do you Search? (I ask since you mention that as the source of the problem) Windows Explorer retains a fixed number of customizations.

TweakUI is one way to view/modify this value:

From the Microsoft Knowledgebase is this information for manually editing that value:

By default, Windows XP and Windows Server 2003 remember each folder's view settings and customizations. This data is limited to 400 folders and is stored in the following registry keys:

• HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell
• HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam

Windows Vista and Windows Server 2008 instead use the following registry key to store this information:

• HKCU\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell

To increase the number of folders that Windows can remember the view settings for, create a DWORD value named BagMRU Size in each of these registry keys, and set its value data to the number of folders that you want Windows to remember the settings for. For example, if you set the value to 5000, Windows can remember the settings for 5000 folders.

And lastly, this article discusses what to do when your "view settings or customizations for a folder are lost or incorrect."