7.4 Cache Flow
As you surf the Web, your browser keeps a copy of everything you download, including pages, graphics, Java applets, and sound files. The copies wind up in a folder known as your browser's cache , which just refers to a bunch of stored files.
Note: Many Web sites include interactive features such as games you can play online. Often, these features are actually small programs that run inside your browser, called Java applets . Java is a programming language that lets developers write programs that can run on many different operating systems, including Windows XP, the Mac, and Linux. An applet is a little program.
When you visit a Web page, your browser first looks at its cache to retrieve whatever it's saved on your own computer before downloading items from the Internet. This process speeds up browsing, because your browser doesn't have to download the same images, text, or other files over and over again. But it can also clog up your hard disk, and some people worry that snoops can peek into their cache and know what sites they've visited ‚ which is in fact possible.
Windows XP lets you customize the size of your browser's cache, its location, and how they system uses it.
Note: The hints in this section apply specifically to Internet Explorer, but all browsers have similar features.
7.4.1 Customizing the Cache
The first thing you should probably do is decrease the amount of disk space Windows XP devotes to the cache. Internet Explorer typically uses about three percent of your hard disk for its cache, which on many PCs can add up to hundreds of megabytes of space ‚ and possibly more than a gigabyte. That's overkill. Here's how to reduce the cache.
First, open the Settings dialog box in Internet Explorer by choosing Tools Internet Options General Settings. Figure 7-11 explains what to do next .
While you're in the Settings dialog box, you can adjust an important feature: how frequently and when you want Internet Explorer to check your cache for stored Web pages. This setting involves a trade-off between your browser's response time and ensuring you see the most current version of a Web page. Here's what each option means and how you should decide:
Every visit to the page . If you choose this option, when you re-visit a Web site, Internet Explorer first checks the site to see whether anything has been updated since your last visit, and then displays the updated files. If the files haven't been updated, it displays them from the cache. If you use a dial-up connection, this can slow down your browsing, though it ensures that the pages you display are always up to date. This setting is a good bet for broadband surfers ‚ those who have high-speed connections such as cable or DSL ‚ since they generally don't have to worry about download times.
Every time you start Internet Explorer . If you choose this option, Internet Explorer checks each Web site you visit for updates only once per session, no matter how many times you drop by. So the first time you visit a site during a browsing session, Explorer checks for new files; but if you go back to that site during the same Internet session, Explorer displays the files from its cache. This speeds up browsing, but you risk seeing outdated Web pages, especially on sites that are updated more than once a day.
Automatically . This setting offers a good compromise between speedy browsing and getting the latest information. When you use it, Internet Explorer calculates how frequently the Web pages you visit are updated, and based on that, determines how frequently to check the Web site instead of the cache.
Never . When you choose this option, Internet Explorer displays the files in its cache, and never checks the Web site for new information. While this leads to the fastest Web browsing, it also means you'll frequently see outdated information when you surf, so it's generally not a good choice unless you're a dial-upper and you frequently visit pages that rarely change.
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Figure 7-11. Shrink the amount of space devoted to the cache by dragging the slider to the left, or by entering a specific number in the edit box. (If you want to increase the cache size, drag the slider to the right.) Depending on how much space you have on your hard disk, you might make the size 50 megabytes or more.
7.4.2 Viewing Your Cache
You can view and open all the files in your Explorer cache. This trick is handy when you remember seeing a picture on a Web page recently, but you can't remember where you saw. If you sift through your cache, you may just be able to hit on it. Simply open Internet Explorer and choose Tools Internet Options; then, on the General tab, look for the Temporary Internet Files section, and choose Settings View Files. Windows Explorer opens your cache folder so you can see what's inside.
Tip: The quickest way to view your Internet Explorer cache is to open Windows Explorer and go to Documents and Settings [Your Name] Local Settings Temporary Internet Files. ([Your Name] is your XP user name .)
Your Temporary Internet Files folder (same thing as your cache) most likely contains a mix of graphics, cookie s , HTML files, Java applets, and other objects from Web sites you've visited. To open any of them, just double-click the icon as you would any other file. XP asks, "Running a system command on this item might be unsafe. Do you wish to continue?" Click Yes to open or run the file.
7.4.3 Cleaning Out Your Cache
Every once in a while, you should clean out your cache and delete all the files there. Doing so frees up hard disk space and makes sure no one can peer into your cache and see what Web sites you've been visiting. (To snoop, all someone would have to do is sit at your PC and follow the directions in the previous hint to examine your cache; hackers may be able to reach your cache, too ‚ see Chapter 11.)
To clean out your cache, open Internet Explorer and choose Tools Internet Options; in the Temporary Internet files section, click "Delete files." If you'd like Explorer to automatically delete these files every time you close your browser, choose Tools Internet Options Advanced. In the Security section, select "Empty Temporary Internet Files folder when browser is closed." This option may make your browsing a little slower when you turn on your computer in the morning and first open Internet Explorer.