Installing a new operating system is definitely a "look before you leap" operation. Your computer's operating system is just too important for a willy-nilly install, so you shouldn't dive blindly into the installation process. To make sure that things go well, and to prevent any permanent damage in case disaster strikes, you need to practice "safe" installing. This means taking some time beforehand to run through a few precautionary measures and to make sure that your system is ready to welcome Windows Vista. Even if you won't be installing Vista for a while, you should still do a few things now to prepare your system.

To that end, the next few sections run through a checklist of items you should take care of before inserting the Vista disc. You might be wondering why there's no "Format Your Disk and Start Fresh" section. That's because you don't need to do that with Windows Vista: Every Vista install is essentially a clean install.

Check Your System Requirements

Now is a good time to make sure that your computer is capable of running Windows Vista. Go back over the system requirements I outlined earlier to make sure that your machine is Windows Vistaready. If you're not sure about something, it's a good bet that Microsoft will maintain a catalog of Vista-compliant hardware, as it does with Windows XP and Windows 2000. You can find the Windows Catalogs and Hardware Compatibility Lists at Microsoft.com.

Another situation in which it makes sense to upgrade your computer in advance of Vista is when you know the new hardware is Vista-compliant (for example, you've seen the device in the Vista Catalog or Hardware Compatibility List). This way, you know that Vista has the appropriate drivers and that the presence of the new device won't cause the installation to crash and burn.

In what situations should you not upgrade your computer before installing Vista? When you know that a critical device is not on the Vista HCL and the device vendor does not offer a Vista driver. Yes, many devices should work in Vista with XP drivers, but that is not universally true. Most major hardware vendors have been working on Vista drivers for many months (if not years) before the Vista launch date, so updated drivers should be fairly easy to come by. If not, either pester the hardware vendor to update drivers, or try a different vendor that has its Vista act together.

Back Up Your Files

Although I'm sure the vast majority of Windows Vista installations will make it through without a hitch, there's a third law that software (particularly complex operating system software) always seems to follow: Murphy's Law (that is, if anything can go wrong, it will). Windows Vista Setup has a recovery option that should get you out of most jams, but you should still make backup copies of important files, just to be safe. Whether it's critical corporate data or precious family photos, you absolutely do not want to be in the position of lamenting, "If only I had backed up those files...."

Even if you're not planning on moving to Vista for a while, it's still a good idea to start backing up now so that you get into the habit of it. Here are some backup notes to bear in mind:

• First and foremost, back up your documents and data. These are nothing short of irreplaceable and should be treated accordingly.

• Back up important items from your Application Data folders, which contain things such as your Internet Explorer Favorites folder, your Outlook Express folder files, and application-specific data. These folders are usually found here:

C:\Documents and Settings\UserName\Application Data
C:\Documents and Settings\UserName\Local Settings\Application Data

• Consider using Microsoft Backup to set up an Automated System Recovery disk and backup set. This enables you to recover your entire system in case the Vista installation fails miserably.

• For maximum protection, consider "ghosting" or imaging your system, which means making a backup copy of your entire system (essentially a second versiona ghost or imageof your system). Products such as Norton Ghost and Acronis True Image make this easy. Ideally, you should have a second hard drive (preferably external) or network share with enough free space to hold the image.

Clean Up Your Hard Disk

If you're upgrading to Vista, to maximize the amount of free space on your hard disk (and just for the sake of doing some spring cleaning), you should go through your hard disk with a fine-toothed comb, looking for unnecessary files you can delete. Here are some candidates:

• Programs you no longer use - Most of us have hard disks that are littered with the rusting hulks of programs we tried a few times and then gave up on. Now is as good a time as any to remove this detritus from your system once and for all. Use the Control Panel Add/Remove Programs icon or the program's own uninstall feature to kick an old program off your machine.

• Old downloads - If you have a folder in which you store downloaded programs (it's a good idea to keep such archives in one place), delete those that you're sure you will no longer need, or those in which a newer version of the program is available.

• Disk cleanup - Run this tool to rid your system of unused temporary files, Internet Explorer cache files, temporary Remote Desktop files, Recycle Bin contents, and more. (In My Computer, right-click a drive, click Properties, and then click Disk Cleanup. Note that this program is not available if you're upgrading from Windows 98.)

Check and Defragment Your Hard Disk

Because hard disks store our programs and, most important, our precious data, they have a special place in the computing firmament. They ought to be pampered and coddled to ensure a long and trouble-free existence, but that's rarely the case, unfortunately. Just consider everything that a modern hard disk has to put up with:

• General wear and tear - If your computer is running right now, its hard disk is spinning away at between 5,400 and 10,000RPM. That's right, even though you're not doing anything, the hard disk is hard at work. Because of this constant activity, most hard disks simply wear out after a few years.

• The old bump-and-grind - Your hard disk includes read/write heads that are used to read data from and write data to the disk. These heads float on a cushion of air just above the spinning hard-disk platters. A bump or jolt of sufficient intensity can send them crashing onto the surface of the disk, which could easily result in trashed data. If the heads happen to hit a particularly sensitive area, the entire hard disk could crash. Notebook computers are particularly prone to this problem.

• Power surges - The current that is supplied to your PC is, under normal conditions, relatively constant. It's possible, however, for your computer to be assailed by massive power surges (for example, during a lightning storm). These surges can wreak havoc on a carefully arranged hard disk.

So unless your computer is brand new, it's a good idea to use the Check Disk tool to scan your hard disk for errors before you install Vista. Note, however, that I'm not talking about the basic disk scan that looks for things such as lost and invalid clusters file system. It's important to fix those, of course, but I'm also talking about a deeper scan that uncovers bad sectors on your hard drive.

Note

Large hard disks are inherently inefficient. When you format a disk, the disk's magnetic medium is divided into small storage areas called sectors, which usually hold up to 512 bytes of data. A large hard disk can contain tens of millions of sectors, so it would be too inefficient for the operating system to deal with individual sectors. Instead, the operating system groups sectors into clusters, the size of which depends on the file system and the size of the partition. For example, on NTFS volumes that are 2GB or larger, the cluster size is 4KB.

When you run Check Disk (in My Computer, right-click the drive, click Properties, click the Tools tab, and then click Check Now), be sure to activate the Scan for and Attempt Recovery of Bad Sectors check box.

When that's done, you should defragment the files on your hard drive. This ensures that the install program will store the Windows Vista files with optimal efficiency, which improves performance and lessens the risk of corrupted data. (In My Computer, right-click the drive, click Properties, click the Tools tab, and then click Defragment Now.)