After you finish reading this post, back up your computer. Stop what you are doing and just consider what would happen tomorrow if all your data disappeared. Not only your data, but all that time you spent customising your machine exactly the way you’d like. All those photos. All that music. All that time installing programs.

Actually, I’d recommend cloning your machine to a bootable external drive. Cloning your machine allows you to get everything back in a similar state, as well as being able to boot from your backup and continue working. Not worth €130? Think again. I’d pay that several times over to have all my data back.

For you MAC users out there, I’ve learned a few things in last couple of days. 1) Make sure your external drive is HFS+ formatted. Even drives that come from Lacie may need to be formatted correctly to be recognised by programs like Carbon Copy Cloner and SuperDuper. 2) If you’re on an Intel MAC, you’ll need to be sure that your partition scheme is GUID, if you’d like to boot from it. Disk Utility will tell you that and allow you to change it. 3) Intel machines can boot from a USB or Firewire drive. PowerPC can only boot from Firewire. 4) Don’t forget you can turn your computer into a Firewire drive by holding down the “t” key when booting. Even if your System Folder isn’t recognised, you may be able to copy your files. 5) Apple won’t sell you a replacement drive for your laptop. You need to send it away to an approved technician. (There are only two in Ireland.)

Stop what you are doing. Go buy an external drive. Backup. Use software that runs automated, scheduled backups. Here’s a good list for MAC.