Old PCs can’t cope with the demands of modern operating systems and software. While upgrading hardware such as memory can help, the better solution is a lightweight operating system. Many Linux distros are designed to be lightweight, with versions of Linux under 500MB and even under 100MB available. If you’re looking for a lightweight operating system for your PC, try these compact, resource-light Linux distros. Linux Distros Under 1GB Most PCs currently ship with 4G of RAM or higher.