Your PC is full of stuff you'd want to keep. Think about your digital photos, no negatives, no prints, what if you lost them?
What about your email, anything in there tat you might want to keep?
On Windows I used to use a Synology server which is a low cost file server. With a simple network connection you can have the last few versions of every document stored ready for instant retrieval. Compucon are the New Zealand agents and would be happy to tell you where to get one.
Couple this with an Acronis True Image backup and you've got it covered.