I have an old computer I’ve been using for a number of years now. Recently, when I switch it on, the date seems to be return to December 2003 and I have to keep changing it to today’s date and time. It goes back to this date next time I turn it on again. How can I make it remember the date?

This is a common problem with old PCs. Computers have a battery that keeps an internal clock running when they are switched off. Like any battery these run down over time and need to be replaced. What you need to do is open up your PC and look around the motherboard for what looks like a silver coin. Most computers use a battery called CR2032, but you’ll find the exact type of the battery by checking out the number on the back of the battery. Once you figure out what it is, you can normally buy a spare from a jeweller’s store or computer outlet. Here’s what it looks like:

This tends to be a specific PC problem, you probably won’t find the same issue on Apple computers or on a PS3. But if you know where to look, it’s not a hard problem to fix.