Hi, I'm new here and joined MDL to learn new tech and stuff. This is my first Thread. Many thanks for the great work you guys do here. It is extremely helpful . I really appreciate it. I can see how bad the Dell support is according to the things I have learned here. I bought a Dell Inspiron 15 5559 i5-6200u laptop couple of days ago with Ubuntu 14 pre-installed. It has Secure Boot, UEFI BIOS, Legacy. The system BIOS version is 1.1.3. Except for Legacy BIOS I have never had to deal with the other two before. I want to install Windows 8.1 Enterprise X64 on this laptop. I have downloaded the following ISO images & will burn a bootable DVD. en_windows_8.1_enterprise_with_update_x64_dvd_4065178.iso en_windows_8.1_enterprise_x64_dvd_2971902.iso Question 1 – Please guide me step by step how to adjust the UEFI BIOS/Secure Boot/Legacy settings? Question 2 – Which ISO is best from above 2 ? I don't know their differences. Question 3 – After installation which program do i use to activate windows? And also please instruct me on anything else i should know in this regard. Thanks in advance for your help.