Every hard drive stores a copy of the history of what has been conducted on it in a hidden file called the index.dat file. Even when you delete Internet history, it's not really completely gone from your computer because a backup copy of it is stored in the index.dat file. The index.dat file also contains history of recent documents and accessed programs. If you want to search a hard drive's history, you have to locate the index.dat file and open it with a program that can read it.
Configure Your Folder Options
Click "Start," click "My Computer" and then click "Search."
Click "Tools" from the horizontal navigation menu bar at the top of the window. Then click "Folder Options."
Click on the "View" tab. Click on "Show hidden files and folders." The index.dat file is hidden, so this will ensure that the file will show up in search results.
Remove checks from "Hide extensions for known file types" and "Hide protected operating system files." You want the extension for index.dat to appear in search results, and index.dat is a protected operating system file that you want to show up in the search results.
Click "Apply" and then "OK" to return to the Search window.
Click on "All Files and Folders." Click the "C Drive" from the "Look in" drop-down box.
Type "index.dat" into the "All or part of the file name" text box, and then click "Search."
Download an index.dat file analyzer onto your computer (See Resources).
Right-click on the index.dat file and click "Open With" and then "Choose Program." Select your index.dat analyzer from the list to open the index.dat file so that you can view the hard drive's history.
Things You'll Need
Index.dat file analyzer
Your hard drive might have more than one index.dat file on it, which is normal, especially if your computer has multiple user accounts on it.
The index.dat file will be blank if it has been cleaned. Some third-party applications like CCleaner clean the index.dat file when used.