The worst moments of our computing lives are all based around the same situation: you've turned your system on, and Windows, for whatever reason, won't start.

Has your computer turned into so much useless metal? Have you lost everything? It's horrible feeling.

Fortunately, there's a simple solution: with a Windows 7 installation DVD, a Repair function could get your PC booting again in next to no time. But if you don't have an installation DVD - and many of us don't these days - or if it's lost or scratched, you'll be in trouble. That's why you need to prepare for disaster before it happens.

Follow our simple guide and you'll have a Windows 7 system repair disc, which you can use to start an unbootable PC - and usually get it working again - in about 10 minutes.

While you're pulling out that spindle of recordable DVDs, we'd also like to suggest another option for disaster recovery: ghosting your drive. Making a bit-for-bit copy of your hard disk might seem a bit extreme, but it's worth doing on a new-ish PC, just so you can always restore it to its default state. Grab a copy of Macrium Reflect Free from www.macrium.com/reflectfree.aspx and use its clone facility - you'll need a stack of discs, but you won't regret it.

Creating a repair disc in 10 minutes

Ensure you're always fully protected against a PC that won't boot

1. Explore Control Panel

Click 'Start', then select the 'Control Panel' option. If the 'View by' option is currently listed as 'Category', click on the arrow to its right and select 'Large icons' so you can see all the available Control Panel applets on one screen. Find the Backup and Restore applet and double-click to launch it. This is where the magic happens.

2. Launch the disc creator

Click 'Create a system repair disc' on the left to run the tool that you need. If you don't see this option, you can also launch the repair disc tool as a separate entity. Simply click 'Start' again, type recdisc into the Search box, and then click on the recdisc link or hit [Return] to fire up the program you need.

3. Find a disc

Locate a blank disc - it can be either a CD or DVD, it doesn't really matter, although we'd recommend a DVD in case the process decides it would like more space. Place the disc into one of your optical drives. Then click the arrow to the right of the currently selected drive, in the 'Create a system repair disc' program, and choose the drive that contains your disc.

4. Click and burn

Click the 'Create disc' button and the program will burn the system recovery files to your CD or DVD. This shouldn't take long - on my computer, with a DVD drive which goes like the blazes, the whole thing is over in around a minute. Then, as the program suggests, I like to label my disc 'Repair disc Windows 7' so it'll be easy to identify in an emergency. You should too.

5. Test carefully

Test your disc in immediately to make sure it works - it only takes a moment. Leave the disc in the drive, close any open applications, and reboot your PC. If Windows loads as normal, you need to change your BIOS setup program to boot from your optical drives first. Check your PC's manual for more advice; there's a specific key you'll need to hold while booting.

6. Boot the disc

When your computer is booting from your repair disc correctly, you may see a message on screen prompting you to 'Press any key to boot from CD or DVD'. If you do, just tap [Space] (or, as you may have guessed, any key of your choice) and repair disc will continue to load. Then you need to choose the option 'Windows Setup [EMS Enabled]' from the menu.

7. System Recovery options

Select your keyboard and click 'Next'. Select your Windows installation, then 'Next' again, and you'll see the recovery options. If you ever find that Windows 7 won't start, boot from this disc, click 'Startup Repair', and Windows should get your computer working again, automatically.

8. Read for (almost) anything

You now know all about the Windows 7 Recovery Disc creation tool. If you've completed these steps, well done - you're protected. Even if Windows 7 won't start, you can always launch the Recovery Disc, then use System Restore, a backup or Startup Repair to fix the problem and get everything back to normal.