Which types of tasks are most likely to make my PC run slower?

1. High-end gaming.

2. Intensive graphics rendering and video editing.
3. Running multiple programs at once.
4. Running disk defragmentation or disk clean-up processes.
5. Scanning for viruses and malware.
6. Installing a lot of applications and programs.
7. Transferring large files.
8. Keeping numerous browser tabs open.