|
BOOT CAMP 132 -- 13/07/00
PARANOIA!
Where have you been today? How easy would it be for someone,
be it a nosey colleague or perhaps someone with more devious motives to pry into
your Internet activities? If you have children with access to a PC do you know
how to keep an eye on what they get up to on the web? Privacy is a highly
emotive issue and in this week’s Boot Camp we reveal some disturbing facts about
what your PC can tell you or someone with more sinister intent, about what it
has been used for.
Every time you log on to the Internet your computer keeps a
highly detailed set of records of the sites you have visited. That much you
already know, but what you may not be aware of is that your PC may also maintain
several ‘secret’ files that cannot be deleted or read by normal means, which
someone with the appropriate software can easily access, but more about that in
a moment.
The focus of our attention is Microsoft Internet Explorer,
far and away the most popular ‘browser’ program on Windows PCs, and very good it
is too but it is a large and complicated piece of software and it pays to be
aware of its hidden depths. Incidentally most other browser programs including
Netscape Navigator and those supplied by AOL and CompuServe etc., also log
information but space precludes us from including them in this weeks article, if
you’re interested in finding out more let us know and we’ll consider it for a
future Boot Camp.
Information about the sites you have visited is kept in three
basic forms: the web site address or ‘URL’, ‘cookie’ data (see Jargon Filter),
and copies of the web pages you have viewed. These are stored – sometimes in
multiple folders -- in several different places on your PCs hard disc drive. The
number and locations of these files vary according to which version of Windows
and Internet Explorer you are using. Generally speaking they are fairly easy to
get at, and control or delete from within Internet Explorer, and Windows
Explorer, though the deletion process is nowhere near as exhaustive as you might
think. Nevertheless, we’ll begin by showing you how to maintain a very basic
level of privacy, enough to defeat a casual snooper from prying into your
business.
URLs of all the sites that you have visited recently are
contained in a folder called History, complete Internet Pages are stored in a
‘cache’ called Temporary Internet Files and cookie data can be found in both
Cookies and Temporary Internet Files; all three are inside the Windows folder.
In addition any text or graphics that you’ve extracted from Internet pages may
also be listed in the Recent folder, also in Windows. To carry out a low-level
cleanup of these files, control their size and how long they are kept open
Windows Explorer and select Internet Options on the Tools menu. On the General
tab you will see Temporary Internet Files and two buttons, Delete and Settings.
Delete empties the cache, clicking on Settings allows you to control the size of
the file. The lower the setting the less it holds, if you set it to zero it
won’t store any pages, but this means you won’t be able to use the ‘Back’ button
on your browser, which will slow down the time it takes to download pages.
Underneath Temporary Internet Files are controls for the
History file. You can empty the file by clicking on the Clear History button and
limit the time it keeps URLs by changing the ‘Days to keep pages in History’
setting. A value of 0 means it will empty every time you exit Windows. Cookie
controls are on the Security tab, click on the Custom Level button and scroll
down the list until you come to Cookies, from there you can enable or disable
cookies, or instruct Explorer to prompt you whenever a site tries to load one on
your PC. To remove cookies from your PC you have open Windows Explorer and
locate the Cookie folder, highlight the ones you want to get rid of and click
Delete; this will send them to the Recycle Bin so remember to empty that as
well.
You can automatically wipe the History file each time you
open Internet Explorer with that most useful of utilities Tweak UI.
Unfortunately these actions only partially eradicate records
of your web activity, quite a lot can of information can be left behind and
there are at least two more files listing previously visited URLs and cookie
data. Bits of Internet pages and images often remain behind in Temporary
Internet Files, which don’t show up in Windows Explorer. To see and delete those
hidden fragments you need a file viewer; the most effective one is ACDSee, which
we looked at in last week’s Boot Camp Top Ten Shareware utilities. The trial
version can be obtained from: www.acdsystems.com/products/download.htm
The more worrying ‘leftovers’ are both called ‘index.dat’;
one is stored in Cookies, the other one lives in Temporary Internet Files. They
are well hidden, and protected by Windows, you cannot delete them from Windows
Explorer, in fact they may not even be shown, but you can track them down using
Find on the Start menu. Windows will not let you open them with Notepad or
WordPad, nor will it let you change the name, but you can see what’s inside, and
give yourself a nasty surprise – especially if you’ve just emptied Cookies and
Temporary Internet files -- by opening it with Word or Excel. You will have to
use the ‘Notify’ function because they’re protected, even when you open it you
still won’t be able to change the contents. There are several ways to get rid of
index.dat files. It can be done from within DOS but this method is fairly
involved and not for novices. The alternative is a specially designed cleanup
program and the best known is Windows Washer. It’s very effective and works with
other browser programs, a Mac version is also available. A 30-day shareware
trial can be downloaded from:
www.downloadplanet.com/washer.htm
Also worth considering is an excellent freeware utility
called Spider, which will let you view the contents of your index.dat files.
This program works with all versions Internet Explorer and is available from: www.fsm.nl/ward/
Next week – BIOS for beginners
JARGON FILTER
CACHE
A file or folder (or section of memory) used to store
frequently accessed information
COOKIE
Small text file, stored on a PC by web sites, containing
access data – passwords, preferences etc. – to help reduce download times on
subsequent visits
URL
Uniform Resource Locator – a
standard Internet address e.g.: http://www.telegraph.co.uk
TIP OF THE WEEK
This one is for advanced Windows users. If you have a second
disc drive with a few hundred megabytes of space on you PC you may get a small
but worthwhile improvement in performance by using it for the Windows Swapfile.
This is a constantly changing file that Windows uses to store program data and
files; by putting it on a separate drive it will relieve the strain and speed up
access times on your main C: drive. Right-click on My Computer, select
Properties and the Performance tab and click on the Virtual Memory button.
Choose ‘Let me specify my own virtual memory settings’ and change the drive
letter to D:\, click OK and reboot.
|