Operating System Performance Boost Needed

The first time the issue showed up, I noticed my software programs were deploying more slowly. Subsequent issues extended to slow booting and an erratic taskbar, which wouldn't load or would disappear completely. Opening settings is a struggle and the screen keeps refreshing. I've recently installed a new software and I suspect that might be the culprit. I'm looking for a professional, experienced with diagnosing and resolving OS performance issues. Key skills include:
- Deep understanding of OS functionality
- Troubleshooting and software compatibility expertise
- Issues diagnosis and resolution skills
- Exemplary problem-solving abilities.