DIY Windows Cleanups for free:
1) Run your Antivirus scanner with a full scan - remove anything it finds
2) Malware Bytes Anti-Malware - do a full scan and remove anything it finds
3) Spybot Search & Destroy - do a full scan and remove anything it finds
4) CCleaner - clean up the temporaries
5) open the Control Panel, open Programs & Software, uninstall unused apps (optional)
6) Defrag - run a few times to optimize the hard drive C:
7) Reboot your computer
Consider using the following free apps to do a standard cleanup on your Windows computer.
1) Anti-Malware
Malware Bytes Anti-Malware
2) Spyware scan
Spybot Search & Destroy
3) Anti-Virus scan
Microsoft Security Essentials
4) Cleanup Temporaries
CCleaner - cleans temporaries and registry
5) Defrag
Start/Programs/Accessories/SystemTools/DiscDefragmenter