Like its predecessors, Windows 8 is sometimes starting up very slowly. What can be done in such case? Well, the very first thing is identifying why Windows is booting slowly; this is often caused by one or more processes running in the background. Unlike its predecessors, Windows 8 features more advanced methods of identifying and diagnosting slow startup programs.
By clicking the key combination CTRL+ALT+DEL you open the Task Manager that was considerably improved as compared to Windows 7. Go to the Startup tab where you have an overview on the programs starting with Windows. From this panel, you may disable any unwanted programs that possibly caused the slow down.
In the Task Manager window, go to More Options button bottom-left side and the click the Startup tab; a list with the startup items along with their startup impact appears. If you see any reports that a specific process is slowing down the machine, select it and go to the bottom-right side of the window and click “Disable“.
Following this procedure should normally lower booting time of your computer but if the problem persists, there is maybe a more complicated issue and you should contact a software engineer.
If you have any questions, just ask in comments so the community can help.