If you've decided that you must wipe out and reinstall Windows, follow the steps over the next few pages to make the process as safe and painless as possible.
Step 3: Create an Image Backup of Your Hard Drive
In the unlikely event that something goes wrong (for instance, you forget to save a copy of an important presentation that you need for work on Monday), an image backup of your hard drive in its current state will let you quickly and easily restore everything to where it was before you started. Resist the temptation to skip this step, as it's your most reliable safety net.
What should you back up to? An external hard drive - they're fast, cheap, and easy to work with. For best results, pick one that's at least twice the size of all the data you have. If your 160GB hard drive has 90GB of data on it, a 200GB external drive will make a good choice. With 500GB and 1TB drives now readily available and reasonably priced, though, I suggest you go as big as you can afford; that way you can save more than one copy of your files to the drive, or even use it to back up multiple PCs.
And what software should you use? Norton Ghost and TrueImage are the two best-known image-backup programs, but they aren't the only ones. Check your regular backup program (you do back up regularly, don't you?) for an image-backup feature, quite likely labelled Disaster Recovery. The backup software that came with your external drive might have something similar, too.
Vista Business and Ultimate have built-in image backup. Click Start, type backup, select Backup Status and Configuration, and press Enter. Click Complete PC Backup, and then choose Create a backup now.
And, as usual, you have free options. I recommend Runtime Software's DriveImage XML.
Remember, though, that an image backup is useless if you can't boot from a CD or DVD to restore it. Both Ghost and TrueImage come with tools for creating just such a disc. If you opt to use Vista's Backup tool, make sure you have either a true Windows Vista DVD or the Vista Recovery Disc available for recovery purposes. You can recover a DriveImage XML backup via the Ultimate Boot CD for Windows.
Step 4: Make a Data Backup
Yes, I just had you create a backup of everything on your hard drive, including your data. But the purpose of that first backup was to add an extra layer of security. This second, data-only backup will make restoring your data, once you reinstall Windows, easier.
See 'What's the Best Way to Back Up What I Need to Back Up?' for two lists (for XP and Vista) of Windows' data-holding folders. But don't worry about the software I recommend in that article - all you need to do right now is drag and copy those folders to a safe location.
As for what location, once again, an external hard drive does well. If you're really paranoid (as I am), you'll use a different external drive than you used for your image backup; it's safer than putting all your backups onto one hard drive. If you have only a few gigabytes of data files, burning them to DVD is a good, cheap solution.
Step 5: Reformat, Restore, and Recover
Now comes the main event. I can't really give you specific instructions for using your recovery tool, because I don't know what recovery tool you have. Just boot into it and follow the prompts. They're all designed to be as simple as possible.