My aunt has been telling my mother that we should delete the contents of our computer history (cookiees) everday.
Should I?
No real need. Cookies aren’t inherently bad; they keep you logged in to boards like this, record shopping preferences and so on, as well as potentially keeping tracks on more private information such as the site that you were at before and after visiting their site. Nothing really dangerous. Deleting them won’t cause any harm, other than irritation from having to log in to some sites again; not deleting them won’t cause any harm either.
She’s telling me that it will save space. My uncle (who used to work for IBM-her and my mom’s older brother, that is, NOT my aunt’s husband!), told her this.
Well, yes, but not much unless her computer has really low memory. Cookies are text files generally no bigger than 1Kb in size (the Straight Dope banner image at the head of this page is 6.8Kb), so that folder isn’t going to get more than a few hundred kilobytes in size unless it’s never ever been cleaned and she does a huge amount of surfing. Really not a storage problem; besides, if she uses IE, the overall maximum size of the temporary internet file cache (which can be much larger than just cookies) can be easily set.
I have had this identical conversation at least twice with the Better Half, who, it must be admitted, knows more about computers than I do. He says, “Cookies don’t take up that much space, and sometimes when you’re busy deleting all those thousands of cookies that bug you so much [I’m the cookie-deleter in the family], you also delete passwords and log-ons for various message boards and news sites, etc. Now, maybe you don’t mind having to retype in all your passwords, but it drives me nuts. So stop doing it.”
So I did.
Anyway. If you right-click on your Cookies file, you’ll see that even though it may have thousands of cookies in it, still it’s taking up only a few MB of space on the hard drive. And if your hard drive is like mine, which has 14 Gig of memory, a few MB is not that big a deal.
So tell your mom that “cookies don’t take up that much space, and besides, it’s a pain in the butt to have to retype all your passwords in.”
However, what she can do is install something like Spybot or Adaware and remove the spyware cookies off there every day–that’ll make her feel like she’s accomplishing something useful, which she will be.
I’ve had both Adaware 5.83 and Spybot, and Spybot removes way more spyware cookies than Adaware 5.83 ever did.
Exactly what Crusoesaid. On occasion, when I have problems accessing a we site due to cookie issues, I’ll clear them, but I’m then annoyed for days having to retype passwords and account numbers in sites I use regularly. If you’re concerned about tracking cookies, which can reveal websurfing habits to site that use that information for targeted marketing, I highly recommend Adaware, a free scumware-removal utility.
Ad-Aware 5.83 is no longer supported by Lavasoft, but Ad-Aware 6.0 is now available and far more comprehensive. However, it doesn’t delete all cookies, just those it deems as spyware.
Your best bet is every now and then – depending on how much she surfs – is to occasionally open click Tools > Internet Options > (Temporary Internet Files) Delete Files. Once done, go the same path, but choose Settings > View Files. The cookies should still be there, and you can usually see what websites they relate to and delete them individually.
(all instructions above IE-specific)
You can also switch off from IE to Mozilla or Netscape or Opera, all of which have built-in cookie controls. For example, if you see a cookie from a site you know you’ll never go to (say one from a banner-loading webpage), you can delete it and keep it from being able to load again.
Remember not all cookies are in your cookie folder. I have found them all over my C–> Windows Folder
I use Netscape and have it set to ask every time a site wants to set cookies. I can allow certain sites, like the SDMB, to always set cookies, and block others. When I first set this up it was a revelation to me just how many cookies might have been set by sites such ‘netmonitor’ and ‘internetracking’ (when the site I went to had nothing to do with any company of this name).
For security purposes I’d always recommend manually setting cookies, which would also save a modicum of memory and make your aunt happy that you followed her advice. 
You can do that with IE as well. Tools/Internet Options/Privacy tab.
That just should not be. Something’s amiss. I suggest starting a GQ thread about it. 
And now it’s nitpick time: Hard drives are not the same as memory. Saying your HDD has 14 gig of memory is technically incorrect, cookies don’t take up a small amount of memory, etc.; ‘storage space’ would be a better term.
As SciFiSam says, the best thing to do is set your browser up to ask you before accepting any cookies. Not only will you be able to see everything that scumware sites are tring to save to your disk, most browsers will let you block sites completely from setting cookies. With Mozilla, it’s really easy - decline a cookie once, and you can set it up so that site can never save cookies again; accept a cokie once, and you can set Mozilla to always allow cookies from that specific server (say, boards.sdmb.com) without asking you again. Since probably 90% of the cookies out there do nothing but track you, you can safely eliminate 90% of the cookies you would otherwise receive, if you know what’s being done on your computer.