How to reinstall Windows

Computer experts have long believed that there’s only one way to completely fix a Windows computer that has slowed down and lost interest in doing its job well, and that’s to start again by wiping the hard disk and reinstalling Windows.

They’re right too: once Windows has been cleared of unnecessary programs and dodgy drivers it works like it’s supposed to, responding eagerly to its operator’s commands.

Although reinstalling Windows is not a task to be undertaken lightly, it’s fairly straightforward if suitable preparations are made and the job is tackled in the correct sequence. In this Masterclass, we’ll show you how.

Pros and cons
There are lots of reasons a clean install of Windows is better than upgrading or repairing an existing copy.

For starters, it involves repartitioning and reformatting the hard disk, which will remove any trace of viruses and other malicious software. The resulting fresh installation of Windows also occupies less disk space than before, and the space it occupies is not peppered with gaps that slow down hard disk access times.

All traces of old programs are eradicated, along with conflicting file associations, unneeded Registry entries and multiple copies of the same system files. Leftover bits of uninstalled software and expired trial programs are also eliminated.

The main argument against a clean install is that it’s a lot of work. You’ll need to back up and later reinstate all your existing data. Every program will have to be reinstalled and reconfigured. You’ll also need to set up Windows so that it works the way you want it to.

The preparation for the clean installation of Windows, the installation itself, the reinstatement of data and the reinstallation of software will take a full day. After that, count on a week of constantly interrupting what you’re doing to make tweaks.

What you’ll need
Some computers are supplied with Windows pre-installed on the hard disk along with a host of utilities and accessories. The source files for Windows and the extra software might be stored in a hidden partition on the hard disk or supplied on CD or DVD as a so-called recovery disc.

Because there’s no standard way to return such a computer to the state it was in when new, you’ll need to follow its supplier’s instructions and use the proprietary discs provided.

This Masterclass is concerned solely with reinstalling Windows XP or Vista from an official Microsoft installation CD or DVD. As well as the installation disc you’ll need the Windows product key displayed on the disc packaging or the case of the computer.

If the Windows disc is an upgrade version of Windows XP, you’ll also need the CD of an earlier version of Windows because you’ll be prompted to insert a qualifying disc during the clean install procedure.

Qualifying versions of Windows are NT 3.51, NT 4.0, 2000 Professional, 95, 98 and ME. If your previous version of Windows is no longer available, you can borrow a qualifying disc from a friend or colleague because no check is made on the product key.

The situation with upgrade versions of Vista is very different. Microsoft did not intend any of the Vista Upgrade discs to be used for clean installs.