You can use this option after update or repair your windows to change new system files to new style.
1. run reloader from all programs and skin pack menu and click on install.
2. after complete repair click on next button.
3. click on finish button , your system will be restart to make change new files to new style.
after restart if you see your system not started its problem with your antivirus so run safe mode and run Reloader again.
After login if you see your icons not change to new style you need to refresh icon cache form here
Note: after run refresh icon your explorer will be closed and you need to logoff your windows with Alt+Ctrl+Delete Buttons.
Note: its better to disable antivirus when you running Reloader.
you can watch video about how to install and unistall a skin pack here