Microsoft's Windows Installation Media Creation Tool [1] enables you to download a clean Windows 8.1 ISO that can be used to re-install the operating system and wipe out all of the preloaded bloatware on any PC.
To do the same with a Windows 7 PC, visit Microsoft's Software Recovery website [2].
From Windows 8.1 Update 1 onwards, there is a built-in PowerShell cmdlet called Export-WindowsDriver [3] that will backup all of your third-party drivers prior to reinstalling the OS.
Export-WindowsDriver –Online -Destination c:\DriverBackup
Once you have created a bootable USB flash drive from the Windows ISO [5], another useful tip is to create a folder called $WinPEDriver$ in the root of the drive and copy the drivers you backed up into here. Windows will automatically install the drivers found in the $WinPEDriver$ folder during installation of the OS.
[1] http://windows.microsoft.com/en-us/windows-8/create-reset-re...
[2] http://www.microsoft.com/en-us/software-recovery
[3] https://technet.microsoft.com/en-us/library/dn614084.aspx
[4] http://www.softpedia.com/get/System/System-Info/Double-Drive...