Windows 8.1 has reached End of Mainstream support and its best to avoid its reinstallation entirely. Windows 10 is a free upgrade to Windows 8.x OEM and you are best to clean install the latest mainstream build of Windows 10 Directly. [URL] You can use the Windows 10 Version 1909 Media Creation Tool to get the latest Windows Installation Media from Microsoft which will automatically input and accept your Windows 8 OEM or Windows 8.1 OEM Product Key embedded in the motherboard UEFI BIOS. Otherwise some Dell systems have Windows 8.1 installation media available when their Service Tag is input into the Dell OS Recovery Tool: [URL]  
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