Computers are getting old very fast. I have 5 computers at home and one of these computers I do not use at all. It has Pentium M processor 1.6GHz and it is about 7 years old.
The easiest and one of the best roles for your old computer might be a file server. Don’t be afraid of the word "server". File server is a computer in your network, that has the primary purpose of providing shared disk access. You can use this shared disk as a shared storage for your documents, images, video files etc. File server doesn’t perform any specific computing tasks. It might be any computer even based on Windows 9x, but I would recommend you use at least Windows XP.
You can ask me why should you have your own file server? I can tell you some good reasons but the most important is – it allows you to keep your files protected. I use my desktop computer as my file server and copy all my documents to it. If something happens to my laptop I can always restore any file from my desktop computer.
You can use any backup software to create and copy backups to your file server or do the copy manually. I do it manually. Not because of my love to manual work, but because I have been doing it for about 20 years.
You can get more advantages from using your own file server if you have more than 1 computer in your networks. You can easily stream music and video from the server to any computer in your network.
Torrent (BitTorrent) – peer-to-peer file sharing protocol. There is no need in dedicated servers to download data from. Anyone can share a file with the world and anyone can download the file right from your computer using Torrent client.
Nowadays Torrent clients are mostly used to distribute illegal files. But there are a lot of legal files you can download. For example, I sometime download Linux distributives.