index.dat files are located in the directory: C:WINDOWSLocal SettingsTemporary Internet Files.
1. Make all files visible in Windows
1.a~ 1. START>settings>control panel>folder options>VIEW tab. (Windows XP)
1.b START>settings>control panel>classic view>folder options>VIEW tab. (Windows Vista)
2. "Show hidden files and folders"
3. Uncheck "Hide extensions for known file types"
4. Uncheck "Hide protected operating system file types"
5. Click on Apply and Ok
2. Navigate to C:WINDOWSLocal SettingsTemporary Internet Files
3. RENAME it to C:WINDOWSTocal SettingsTemporary Internet Files (Tocal can be anything)
4. You'll get a windows warning that renaming "could make some programs ect.....just do it.
5. Open internet explorer and go to one of your favorite sites (testmy.net) brows a little, visit several pages,
6. Using "Find files", make a search of your copmputer for "index.dat". There'll be two besides the normal ones: the OLD one in "Tocal Settings", and a new, smaller one in "Local Settings".
7. Delete the entire "Tocal Settings" directory, this should do it forever for the index.dat gunk !