The methods for deleting the index.dat files are rather complicated or difficult. Many tools are posting that they can delete index.dat, but it shows they cannot and they do not more than the operating system also!
So I have found a tool that is really working and that is very fast, small and free!
This tool is
UNLOCKER 1.8.5 By Cedrick 'nitch' Collomb
"Unlocker is an explorer extension that allows you with a simple right-click of the mouse on a file or folder to get rid of error message such as error deleting file or folder, cannot delete folder: it is used by another person or program. Unlocker can unlock files, folders, dll, and can also delete index.dat without restarting your computer."
Unlike other methods, no shutdown or reboot is required. It does not start with a normal program main window, but only as a context menu item. If you want to delete the index.dat file in the history folder, you cannot navigate to this file as it is hidden and does not show directly. The following screenshot is made from the open dialog in Index Reader.
You can use Index Reader, navigate to the hidden folder "History.IE5" and right click on the index.dat file and select "Unlocker". A new window will open that shows all processes that have locked the index.dat file. Select delete or copy in the drop-down box left. Click on unlock all. The file is not moved to the recyle bin, but deleted immediately. I have tried it under XP Home. After deleting the file, there is no danger for Internet Explorer to work. At the next program start, the index file will be created with a size of only 16 KB. Otherwise, when deleting history in Internet Explorer, the index.dat file will keep its maximum size that it had before deleting.
Congratulation and thanks to Mr. Cedrick Collomb.
On his web page there is a nice comparison of cleaning programs:
