1. The Motherboard. Every internal part of a computer must fit onto or connect to the motherboard for it to work.2. The Power supply or PSU provides the computer with power.3. The CPU, which is the brains of the computer.4. Random Access Memory or RAM.5. You can find a Floppy Drive depending on how old the computer is.6. CPU and internal cooling fans, which keep the computer cool and help prevent the computer from overheating.7. The Hard drive, or HDD. All you data is stored on your Hard drive.