Linux runs on old computers, doesn't it? Many people have heard or read that also old computers can run Linux. This is true, but you should not expect to be able to run newest multimedia programs or play 3D games on old hardware. If you just want to read and send email, write a book, browse the Internet, learn to program, or maybe write a book with your computer, read on. Only your imagination can limit the uses of old hardware or modern hardware with low specifications.
Save your money for better uses. You don't have to buy a new computer just to update the operating system. Even computers one can get free or buy for a few euros or dollars can be used to run a modern desktop with lightweight software. Everyone living in the industrial world can afford a used computer for running a free operating system. Thus Linux helps to cross the digital chasm between those who can afford to participate in the modern computerized world and those who cannot.
If your computer is not older than ten years, it definitely can be used as a Linux desktop. You can either use a distribution specifically tailored for older hardware or you can use almost any modern distribution and customize the installation for your needs. You might have to hack some configuration files with a text editor and forget using the latest GNOME or KDE. You might have to install the distribution of your choice in text mode. You might need some help in tweaking your system to run as smoothly as possible.
But it can be done. And you can do it, too!