No, you don't need to install anything. All you do is enter the Pro product code though add features and 8 will be upgraded to 8 Pro. All the files needed to do this are already on your system. None of your files will be lost and none of your custom settings will be changed.
Computer Type PC/Desktop System Manufacturer/Model Number Asus OS Windows 10 Education 64 Bit CPU AMD Phenom II X4 980 Black Edition Deneb 3.7GHz Motherboard ASUS M4N68T-M V2 µATX Motherboard Memory 8GB 4GBx2 Kingston PC10600 DDR3 1333 Memory Graphics Card NVIDIA Geforce GT640 2 Gig DDR3 PCIe Sound Card VIA VT1708s High Definition Audio 8-channel Onboard Monitor(s) Displays 22" LG E2242 1080p and 2 19" I-INC AG191D Screen Resolution 1280x1024 - 1920x1080 - 1280x1024
Keyboard Logitech Wireless K350 Wave Mouse Logitech M570 Trackball and T650 TouchPad PSU Thermaltake TR 620 Case Power Up Black ATX Mid-Tower Case Cooling Stock heatsink fan Hard Drives Crucial MX100 256 GB SSD and 500 GB WD Blue SATA Internet Speed 80 Mbps Down 30 Mbps Up Browser Internet Explorer 11 Antivirus Windows Defender Other Info HP DVD1040e Lightscribe - External USB2