Dave has a laptop with two hard drives with various ages. When is it a good time to replace the old drive? Leo says that hard drives fail over time. Google says that they will fail a lot at first, and then then to zero the first few years, and then about 8% a year after that. So if you're drive has been running that long, it may be one of the well put together ones. Hard drives are cheap so just keep your data backed up. Use it until it fails and when it does, your data's already backed up and ready for the new hard drive. Spinning drives also tend to fail gradually. So when it starts getting flaky, it's time to replace them.