Hi Everyone, I'll begin by giving a brief background on whats going on. I have a Dell Inspiron 660s - Its a few years old. My hard drive was failing so I had to replace it. I replaced the hard drive and re-installed the original OS media (Windows 8). After I was finally up and running I downloaded some drivers from dell and did some windows updates. The goal was to try and get my PC back to or at least close to what I had before the hard drive failed. I had windows 10 before the hard drive failure. In order to get windows 10 back I had to download Windows 8.1. Everything seemed to go smoothly until I had to restart and allow the download to finish. I get upto 82% and it stops there for a long time and then eventually goes to a blue screen error stating the problem is a Bad_Pool_Caller. After the bluescreen dissappears it restores back to Windows 8. Another message appears when I get to the desktop stating Windows 8.1 installation unsuccessful error code 0xC1900101 - 0X30018. I would appreciate your help as I am stumped by what the issue is. Thanks.