I made my system look like Windows 8.1, took some time and work. This system originally came with 8.1 preinstalled.
Changes, Software and themes used:
Stardock Windowblinds with theme: 8 for 7 by 2of3
Stardock Iconpackager with theme: W 7 by Butch123
Stardock Start10 with Custom start button: Original Win 8.1 Start Button_By Rana
7+ Taskbar Tweaker to get bigger taskbar icons
Winaero Tweaker to get Windows 8 style network flyout, older volume slider, Windows Photo Viewer, and to disable action center, among other tweaks.
Changed File Explorer Icon with ico icon from the W 7 theme by Butch123
Changed Firefox Icon to the older style icon
Wallpaper: One of default 8.1 wallpapers that also comes with Windows 10
Enabled titlebar to Firefox to allow skinning with Windowblinds
Used Microsoft Paint to create a texture png file to use accent color from wallpaper.