How to make Windows 8.1 Faster and Improve Its Performance (Full HD)

1. Disable unnecessary startup programs.
2. Set unnecessary services to manual, such as:
Application Experience
Computer Browser (If your computer is not connected to any network)
Diagnostic Policy Service
Distributed Link Tracking Client
IP Helper
Offline Files
Program Compatibility Assistant Service
Portable Device Enumerator Service
Remote Registry (Always disable it for Security purposes)
Secondary Logon
Security Center
Server (If your computer is not connected to any network)
TCP-IP NetBIOS Helper (If you are not in a workgroup network)
Windows Error Reporting Service
Windows Image Acquisition (WIA)
3. Untick Windows Explorer capabilities like:
Display file size information in folder tips
Hide empty drives in the Computer folder
Hide extensions for known file types
Show encrypted or compressed NTFS files in color
Show pop-up description for folder and desktop items
4. Set power plan to High Performance