Buy new Powerbook. Also buy USB external hard-drive to back it onto. Do so regularly.
Home desktop starts making clicky-whirring noises of death. Live with this for a little while, but eventually get The Fear for my data.
Open up the USB external hard drive and rescue from it the IDE drive it stores things on. Put that into desktop.
Install windows, Civ IV, City of Heroes, Ubuntu etc.
Play happily for a month or so.
Back powerbook up to work desktop.
Stage six. (This morning)
Turn on home desktop. Smell strange burning smell. Swear, turn off computer, check all connections, turn on computer.
Examine hard drive rescued from USB enclosure. Notice carbonisation of areas of main board.