Reinstall Windows Without Losing Your Data

PC World - How did things get this messed up? Windows has slowed to a crawl. Programs won't run. The free firewall you installed last year won't update or uninstall itself.

System Restore hasn't helped; neither have your assorted cleanup and antimalware programs. Only one option remains: Reinstall Windows and start from scratch.

I'm not going to lie to you--this is a scary and time-consuming job. Your PC may be unusable for a day or more. You could even lose all of your data.

And let's face it: You'd be wise to avoid this chore if at all possible. If someone in tech support tells you to do it, get a second opinion, and then a third.

If you have to reinstall--and sometimes it is necessary--here's how to make the process as safe and painless as possible.

Gather What You Need

You'll have to collect a few things before you can begin.

First, you'll need your recovery tool. What's that? If you're using the version of Windows that came on your PC, it's probably in a hidden partition on the computer's hard drive. That partition contains the information necessary to restore the hard drive to its factory condition.

Obviously, a hard-drive partition is not something you have to gather. But if your PC is a few years old, the recovery tool may be on one or more CDs or DVDs instead. Find the discs that came with your PC and see if anything looks promising. Alternatively, check the PC's manual to learn what kind of recovery tool came with the machine, and, if it's on a partition, how to access it.

If you upgraded Windows since you bought the PC--for instance, going from XP or Vista to Windows 7--the upgrade disc is now your recovery tool.

If you can't find a recovery disc, and the PC has no hidden partition (or offers no workable way to access that partition), contact the system manufacturer to see what they can do for you. Read "How Do I Restore Windows If I've Lost My Restore CD?" for details.

After Windows installs, you'll have to reinstall all of your programs. Collect all the original discs or downloaded installation files, and all of your license numbers.

You'll want an empty external hard drive with a capacity at least as large as your existing hard drive. Another external hard drive will come in handy later. That one doesn't have to be empty; you'll need only a part of it.

Finally, you'll need time. The best-case scenario for a reinstall is a day. The worst case: three or four days. You'll be spending a lot of that time waiting, so get a good book, too.