Dell Inspiron 15 3531

Started working a Dell Inspiron 15 3531 for a customer.

He wanted it downgraded from Windows 8.1 to Windows 7. I tried to install Windows 7 from a USB since this machine does not have a disc drive. I found out that it using a UEFI system, which was new to me. The machine would not load my USB in Legacy mode. I did some research and learned that I had to update the system BIOS to be able to load the USB drive.This System had the worst Malware infection I had seen in a while. The Malware was preventing me from running the BIOS update program. so i started out running Rogue Killer to stop anything that shouldn't be running on the system and tried to remove what little it found. I then ran Spy-bot search and destroy followed by Malware-Bytes. Finally I ran Adaware to finish of the system. still instances of ads popping up, after 20 mins or so the machine became almost unusable. No luck with the BIOS updater still. I managed to get the system to finally go into the recovery setting and I reinstalled Windows 8.1. with this new install running clean I got the BIOS updater to run. I installed Windows 7 and all the common Anti-malware programs I put on a machine.