Most malware doesn't intentionally set out to damage your PC, that's bad for business - the authors want their creations to stay hidden, so your system remains infected for as long as possible. But whether it's through programming bugs, partial clashes with antivirus software or other reasons, a serious infection can sometimes trash your PC to the point where Windows will no longer boot. And what do you do then?

Fear not. Here are five free downloads that will allow you to create CDs or USB drives that you can boot your system from as well as letting you locate and remove the malware.

Paragon Rescue Kit 11 Free Edition

Paragon Rescue Kit 11 Free Edition is a professional disaster recovery toolkit that could be all you need to get an unbootable PC working again. The software comes in the form of an ISO file, which the setup program will burn to CD or DVD. Boot your PC from this instead and you'll launch a collection of essential troubleshooting tools.

Norton Bootable Recovery Tool 3.5

Download the Norton Bootable Recovery Tool Wizard via another system, and it'll quickly create a CD, DVD or USB flash drive containing stand-alone Norton antivirus tools. Boot your stricken PC from this, and it'll scan for infections, attempt to remove them and repair any damage, and your system could be back in working order in just a few minutes.

AVG Rescue CD v100.110314a3732

The AVG Rescue CD is a bootable ISO image that comes with a range of tools to help you clean up a virus-infected PC, fix hard drive problems, and get an unbootable system working again.

Burn the disc to a CD, boot from it, and the integrated antivirus engine will attempt to update itself over the internet, or using a local folder. You can then run a full system scan to check for threats. And as any infection won't be active (because you've booted from the CD, not your PC), it won't be able to interfere or hide from the scan, and the chances of a successful cleanup are correspondingly much higher.

Avira AntiVir Rescue System 2011.07.01

Avira AntiVir Rescue System is a Linux-based boot disc that will detect and remove malware from a damaged PC. Booting from a separate CD means that stealthy malware like rootkits will find it more difficult to hide, and you'll have a much better chance of detecting and removing them.

System Rescue CD 2.1.1

System Rescue CD is a mini-Linux distribution on a CD that can be used to recover or repair a broken system. Although it is a Linux system, it can be used to repair Windows computers too, and includes a number of tools specifically for this purpose.