when browsing containing directories, therefore allowing anybody using the system to look at and even change and remove their Internet data. Some spyware target the index.dat file for unauthorized reading and/or editing. Computer forensics commonly look at index.dat as part of their analysis of computer use. Removal tools Various free programs (among them Red Button, CCleaner, and Index.dat Suite), can completely remove index.dat files until they are recreated by Windows, though CCleaner, and perhaps the others, does not delete the hidden index.dat file in the Temporary Internet Files directory, which contains a copy of the cookies that were in the Cookies directory. However, if Secure Deletion is enabled in CCleaner then this will effectively wipe the contents of this file although the size will continue to increase with use. Supported on Index.dat is only available up to Internet Explorer 9. Internet Explorer 10 and 11 do not have index.dat files. Instead, Internet Explorer 10 and 11 use WebCacheV01.dat. References External links Windows Networking Team blog about Index.dat (followup Q&A) How to remove index.dat (Site has broken links and the info is outdated) A Cleanup API for Windows - details on how to delete index.dat files Windows 'index.dat' Parser command-line tool for Windows, Linux, Mac OS-X Windows administration Internet Explorer Computer file formats