How can I suppress those annoying Thumbs.db files in Windows Vista and Windows 7?

Using Group Policies

So, with more specific googling, I've discovered how to do it from a post here, for editions of Vista and Windows 7 that come with Group Policy Editor. (Unfortunately, GPE doesn't come with Windows 7 Starter, Home Basic, or Home Premium. A solution for these operating systems can be found in the second part of this answer.)

Here are my own detailed instructions, written against Windows 7 but likely the same for Vista:

1. Run gpedit.msc directly using the Start menu. (You may also be able to find an Edit group policy control panel searching by name, but I couldn't find its icon listed anywhere under "All Control Panel Items". Go figure!)
2. In the left-hand pane, expand User Configuration, then Administrative Templates, then Windows Components.
3. Under Windows Components what was just expanded, select Windows Explorer.
4. In the right-hand pane, sort by Setting, then scroll down and find the setting named "Turn off the caching of thumbnails in hidden thumbs.db files". Double-click it, set it to Enabled, and then click Apply.
5. Log off Windows, and then log back on again.

Within Windows Explorer, you should now be able to delete the Thumbs.db files that you come across on the network (as long as another machine isn't currently locking the file), and the computer shouldn't create them again.

Also worth knowing: In Vista and Windows 7, Thumbs.db applies to network folders only. For local folders, Vista and Windows 7 instead save thumbnail cache information to a database in a local folder at %userprofile%\AppData\Local\Microsoft\Windows\Explorer

Using the registry

The registry equivalent for disabling Thumbs.db creation on network shares in Windows Vista and Windows 7 is:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\Explorer]
"DisableThumbsDBOnNetworkFolders"=dword:00000001

If you place that content in its own text file (e.g. with Notepad) with a .reg extension, you can double-click to import on any Windows Vista or Windows 7 machine to apply the setting. Be careful editing your registry directly.

Thumbs.db is a hidden file, so the easiest way to not see it as litter would be to simply tell Windows to not show hidden files. Of course if you use the command line a lot or have other hidden files you need to see then this won't help.

I found an article that mentions the ability to disable thumbnail caching by modifying a registry key. If the option to disable thumbnail caching is missing in Vista / Windows 7 then maybe you can still do it that way.

1. Open the Registry Editor (regedit.exe).

2. Navigate to the following registry branch:

   HKEY_CURRENT_USER\Software\Microsoft\Windows\ CurrentVersion\Explorer\Advanced\

3. On the right pane, double click on DisableThumbnailCache value, and set its value data as 1. If the registry key of DisableThumbnailCache does not exists, create a new DWORD value with that name.
4. Exit Registry Editor.
5. Logoff and login again, or restart the computer for the changes to take effect.

Another option may be to simply turn off the display of thumbnail previews in Windows Explorer:

1. Click on the Start button, then on All Programs, follow by Accessories.
2. Run Windows Explorer.
3. In Windows Explorer window, click on Organize button on the menu/shortcut bar.
4. In the pull down menu, click on Folder and Search Options.
5. Folder Options dialog window will appear. Click on View tab.
6. Under the Files and Folders tree heading, check (tick) the checkbox next to Always show icons, never thumbnails option.
7. Click the OK button.

There's a registry key you can change to turn off thumbnail caching.

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\DisableThumbnailCache

Set it to 1 to disable caching.

Details here.