What are the most common causes of slow PC performance?

1. Too many programs running at the same time

2. A virus or other malware infection
3. An outdated operating system
4. Outdated or corrupt drivers
5. Not enough memory (RAM)
6. Insufficient hard drive space
7. Hardware issues, such as a faulty or overloaded power supply or a bad processor
8. Fragmented hard drive or excessive disk usage
9. Poorly written software or too many programs running in the background
10. Corrupt/fragmented system files or invalid registry entries