When the index.dat files with all their contents get deleted, Windows reinstalls fresh "empty" index.dat files as soon as you restart Windows. No harm is done. I use the free CCleaner. See here for more information. That's not to say that all such cleaners are perfectly safe. Some may not be.

Am I missing something here? Why can't you just do a Windows Search for "index.dat" and then Shift-Delete everything that comes up?

Windows won't let you. Try it and you'll get an error message.

BTW, it can be deleted through DOS too, though.

I just did. I had no problems shift deleting them.

Hmmm. I was able to delete some but not all. How about the index.dat files under Documents and Settings particularly under your user name?

can't delete that one.

When you posted about Shift-Delete, I only tried it on that one and when it didn't work, I didn't try it on the others. After your next post I did try some of the others and found that it did work on them but still not the first one. I haven't tried every single one yet.

I imagine the only ones you'll have problems with are the user ones in Documents and Settings. You won't be able to delete your own because its still in use, and you won't be able to delete other user's files unless you have privileges to do so. I just posted Shift-Delete because that makes them really gone rather than just moving to recycle bin.

I didn't try it for everything I found either, mainly because I don't have any reason to go deleting my index.dat files.

That brings us back full circle. For the paranoid or perhaps terminally tidy among us, we want to periodically delete our own index.dat files for a couple of reasons. As they continue to grow and accumulate records of the internet sites we've visited, eventually they can take up a lot of space. Also, if you prefer not to have a record of your browsing history kept on the PC, you'll want to get rid of it for that reason.

I noticed that in Windows 98SE you can't get rid of any index.dat files as you can some in XP. So you would have to go to DOS or use a third party program such as Ccleaner.

That said, I realize not everyone is concerned about it. Besides, the easiest way around it is use Firefox or similar browser. It doesn't bother with index.dat type files.

Does going to Internet Options in IE and deleting Cookies, Files, and clearing History not take care of that?

I don't believe so. Not through Internet Options because as long as you are logged on, the index.dat files (for your account) are locked. They can be manually deleted but you would have to logon as admin, locate them and delete them one at a time. If you are the admin account, you have to use or create another admin account to delete them. At least this is my understanding of how this works.

The appeal of using a third party cleaner it that it finds them all at once and you're done. Technically, I think you're done upon restarting but it's still simpler.