By default, the Windows Recycle Bin sets aside 10 percent of the space on each disk partition in your system for storage of deleted files, up to a maximum of 3.99 GB. If you have a 400GB hard drive divided into four partitions, the Recycle Bin could be using up 16 gigabytes of storage. To adjust its appetite to a more manageable level, right-click on the Recycle Bin icon and choose Properties from the shortcut menu. The resulting dialog box contains a Global tab and an additional tab for each hard disk partition that has a drive letter.

Use the slider controls on the Global tab to decrease the percentage of space allotted to the Recycle Bin for all drives on your system. Unless you routinely work with very large files, setting aside a maximum of 1 GB per drive letter should be sufficient to prevent waste and still allow you to recover a file you delete accidentally.

If you shoot lots of digital pictures, learn how to take advantage of information called metadata to keep track of extra details. Image metadata is nonpicture information that’s captured and stored within a picture file. Most digital cameras use the Exchangeable Image File (EXIF) format to store metadata when saving pictures; images may also include metadata that conforms to the International Press Telecommunications Council (IPTC) and Adobe’s Extensible Metadata Platform (XMP) standards. (To learn more about the EXIF standard, visit http://www.exif.org; for more details about XMP, see http://www.adobe.com/products/xmp/overview.html.)

EXIF metadata typically includes the date and time the picture was taken, the width and height of the image (in pixels), the resolution (in dpi), and the color depth. Depending on the camera you use, metadata can also include technical information such as the camera model, flash mode, aperture, and exposure time. Some high-end devices even allow you to add audio annotations to images and store them in the same file.

A few bits of metadata are available in the ScreenTip that appears when you pause the mouse pointer over an image file.

Windows XP doesn’t allow you to edit image metadata. But you can use it to sort and organize image files in Windows Explorer. To see all available metadata for an individual image file, right-click the file icon and then choose Properties. On the Summary tab, click Advanced to display a scrolling list of available metadata properties and values. Image data appears above the Description data, as shown here.

To really take advantage of metadata, you need to customize the Windows Explorer window so that metadata information is visible. To do so, switch to Details view, right-click any column heading, and then select the names of available fields to make those columns visible. Click More at the bottom of the list to see all possible fields. If you add the Date Picture Taken column, for instance, you can then click the column heading to sort by this field and gather pictures that were taken around the same time.

[Note: This tip is adapted from Windows XP Inside Out, Second Edition.]

If you regularly use Explorer’s Details view, here’s a convenient keyboard shortcut you should know about. After opening an Explorer window in Details view, hold down the Ctrl key and press the Plus (+) key on the numeric keypad. This shortcut instantly and automatically resizes each column based on the width of the longest entry in that column, so you can see all the file details.

You’re doing a fresh installation of Windows XP. Is there a way to download service packs and updates so that you don’t have to go through a long, long update process before you can use your computer? Yes. In fact, this method is especially useful if the new computer has only a dial-up connection but you have access to a high-speed computer elsewhere.

The Windows Update Catalog allows you to search for specific updates depending on the version of Windows you currently have installed. If you only have the original release of Windows XP, choose Windows XP RTM (Home Edition) or Windows XP Professional RTM from the list. If you have downloaded and installed Service Pack 2 separately, choose the SP2 option for your version of Windows. (If you’re looking for drivers, click Find driver updates for hardware devices and search by category.)

After you click Search, you’ll see a list of available downloads, arranged by category: Critical Updates and Service Packs, Multi-Language Features, Recommended Updates, and so on. Click the Add button for an individual update to make it part of your download basket. Click the Download Now button to fetch the files you’ve tagged. You can then burn the files to CD or other media to make them available for installation.

One of the options available on the Screen Saver tab of Windows XP’s Display Control Panel is the My Pictures Slideshow.

It’s a great alternative to the bouncing Windows logo. Select this screen saver and click the Settings button to specify which pictures you want to use (hint: it helps to copy your favorite pictures into their own folder and use just that location), how often you want the images to change, how big the pictures should be, and so on.

Environment variables contain information about the environment for the system and for the user who’s currently logged on. Knowing how to use these variables can save you time and keystrokes in batch files and shortcuts and at the command line. In addition, some programs use environment variables to determine where to store user data and temporary files. To use an environment variable in a command or a dialog box, you surround the variable name with percent signs; this tells Windows to look up the current value for that variable in the registry and use that value in the command or path where you entered it.

Two environment variables that I use regularly are %appdata% and %userprofile%. By typing either of these strings in the Run dialog box and pressing Enter, I can jump straight to the Application Data folder or the root of the User Profile folder for the currently logged-on user. I don’t need to know what drive Windows is installed on, and I don’t need to know the name of the current user. Similarly, typing cd %allusersprofile% at a command prompt switches to the All Users profile folder, where shared documents and settings are stored. In a default installation, the full path name is nearly twice as long: C:\Documents and Settings\All Users. You can also use environment variables to create shared shortcuts that work differently for each user. A shortcut that points to the %UserProfile%\My Documents folder, for instance, will always open the My Documents folder of the user who’s currently logged on.

Windows XP creates a group of default system variables, including several that define the location of Windows system files. Only an administrator can change a system variable. However, any user can add, edit, or remove user variables, which are exclusive to the user who created them and can be used in scripts and batch files.

To view and edit all variables, open the System option in Control Panel, and click the Environment Variables button on the Advanced tab. Click the New button to add a variable name and value, click the Edit button to change an existing variable, or click the Delete button to remove a variable.

You can also see a list of all currently defined environment variables by opening a Command Prompt window and entering the set command.

Yet another Web site posted yet another “tip” today recommending that you clean out your Prefetch folder to improve performance of Windows. Arrrggghhh! I’ve written about this repeatedly (here and here and here, for instance), but the message doesn’t seem to be spreading very fast. Maybe this quote from “Misinformation and the Prefetch Flag” by Ryan Myers, a developer on Microsoft’s Windows Client Performance Team, will help:

XP systems have a Prefetch directory underneath the windows root directory, full of .pf files — these are lists of pages to load. The file names are generated from hashing the EXE to load — whenever you load the EXE, we hash, see if there’s a matching (exename)-(hash).pf file in the prefetch directory, and if so we load those pages. (If it doesn’t exist, we track what pages it loads, create that file, and pick a handful of them to save to it.) So, first off, it is a bad idea to periodically clean out that folder as some tech sites suggest. For one thing, XP will just re-create that data anyways; secondly, it trims the files anyways if there’s ever more than 128 of them so that it doesn’t needlessly consume space. So not only is deleting the directory totally unnecessary, but you’re also putting a temporary dent in your PC’s performance. [emphasis in original]

Bottom line: You will not improve Windows performance by cleaning out the Prefetch folder. You will, in fact, degrade Windows performance by cleaning out the Prefetch folder. I’ve done performance testing that establishes this definitively. In all the many sites that offer this bogus tip, I have yet to see a single piece of actual performance testing.

Oh, and for anyone who cites this TechRepublic article as a source, let me just say that it contains more serious factual errors than I can count. For instance:

As you boot your workstation or access programs on your workstation, XP’s prefetcher copies portions of those files to the Prefetch area of your hard drive.

That’s completely wrong. The files in the Prefetch folder contain lists of pages that that should be loaded when a program starts. Each file is essentially an index. Windows XP doesn’t copy portions of any files to the Prefetch folder.

When your workstation boots, XP prefetches portions of the files you use most frequently and has any application you’ve recently run waiting and ready to go.

This is equally absurd. If this were true, it would mean that Windows was actually loading into memory every program you’ve ever used, every time you start Windows. That’s not the way it works at all. When your PC starts up, Windows looks in the Prefetch folder to determine how best to load Windows. It doesn’t do a thing with the .pf files for applications (unless, of course, you’ve configured one of those apps to start up with Windows).

If you’re frequently using the same few applications over and over again, prefetching can greatly increase the apparent speed of a system. Rather than waiting for you to click an icon to start a program, and then loading all of the associated files, libraries, and pointers necessary to run the program, XP has all the components of your programs preloaded. When you click an icon to start the program, most of the hard work is already done.

The author just made this up. The .pf files don’t get used at all until you run a program. What actually happens when you click an icon is that Windows uses the information in the Prefetch folder to decide which program segments to load and in what order to load those pages. There’s plenty of documentation for this, including Ryan Myers’ article and this definitive article by Mark Russinovitch and David Solomon, Windows XP Kernel Improvements Create a More Robust, Powerful, and Scalable OS.

The drawback to prefetching is that XP will prefetch a program even if you use it only once or twice. XP will retain a copy of a portion of it in the Prefetch folder. From there, it will prefetch the program, taking resources from your workstation even though you may have no intention of ever using the program again.

Again, the author just pulled this out of who-knows-where. When you run a program, Windows creates a .pf file for it in the Prefetch folder. When you run the program again, Windows looks for this .pf file and uses it to determine how to load the program. The hash doesn’t contain any portion of the original program code. If you never run the program again, that .pf file never gets used, and in fact it gets deleted eventually.

I used to write for TechRepublic. I’ve tried to contact someone there to get them to correct this silly article but have yet to receive a response. It would be really, really great if some of the other sites that have propagated this urban legend would also correct it.

In yesterday’s tip, I explained how to move the My Documents folder. To move the default folders that Windows XP uses for music, pictures, or video, you use a slightly different technique: Select the folder you want to move (My Music, My Pictures, My Video), hold down the right mouse button, and drag it to its new location. When you release the mouse button, choose Move Here. Windows XP automatically updates all references to the folder, including those in the Start menu.

This tip is especially useful if you have a large music or video collection. By moving the My Music or My Videos folder (or both) out of My Documents, you greatly reduce the size of your documents folder and make the task of backing it up faster and easier. A separate drive is the ideal location for bulky music and video files.

The My Documents folder is the default location for your data files. If disk space is at a premium, you might choose to relocate this folder. For instance, if you add a second hard drive to your system, you might decide to use it exclusively for document storage. Here’s how to relocate all your data files to the new drive.

In Windows XP, click the Start button and then right-click the shortcut for My Documents. Click Properties. On the Target tab, click Move and choose the new location for the folder. (If necessary, you can create a new folder using the Browse dialog box.)

When you click OK, your document files are moved to the new location. Clicking the My Documents icon on the Start menu or in a common dialog box now takes you to this folder instead of the original location.

One caution: Be aware that some programs (notably Microsoft Outlook and Outlook Express) continue to store data in the hidden Application Data folders within your user profile. When you move your My Documents folder, these files remain in their original location. Make sure your backup strategy includes all your data files, not just those in the My Documents folder.