If it has been running without a reinstall since 2009. I'd say it is due for a clean install of Windows to clean out all the years of crap. Then restore your files from a backup and reinstall your software.
Failing that. Run a malware scan with Malwarebytes.
Install CCleaner use it to
- Cleaner: Run Cleaner and clear out junk files. I add check marks for Windows Log Files, Windows Error Reporting, DNS Cache, Windows Event Logs, Old Prefetch Data and User Assist History.
- Tools: Uninstall software you no longer use.
- Restart computer
- Disable unneeded Startup items in Windows and Scheduled Tasks. Most aren't need. Leave on anything that updates software you use like Adobe, Google, Flash, Anti-Virus.
- Restart your computer
- Registry: Clean the registry after you restart. Be sure to backup the registry on the rare chance it tanks your registry. Run the clean several times until it stops popping up new items cleaned. The chance is very slim you will have to reinstall Windows. It does exist. It hasn't happened to me yet in the last 8 years of using this on client computers.
- Restart your computer
If you have multiple anti-virus. Remove all but one. Avira is my preferred AV, free or paid.