Do I Have A Rootkit? Will Rescue Disk Find And Fix That?

I use BDTS on my desktop. The problem is on my laptop (that was not using BDTS at that time):


I upgraded Win 8 to 8.1. After a restart (part of the upgrade process), the laptop would not boot into Windows. I had to repair my installation and reset the computer (losing all my files and setting it up as a new Windows 8 installation from Samsung's hidden restore partition). Even that would fail to boot into Windows 8 after Windows Update. Repair -> Reset PC -> Install from hidden partition -> Windows Update -> Windows 8 fails to start-> Repair -> Reset etc.


This cycle stopped when I disabled UEFI and Safeboot in my BIOS. Then Win 8 installed (into a "back to Factory" condition), Undows Update worked, Win 8.1 upgrade worked. UEFI and safeboot are dtill disabled as I try to restore my personal files from backup.


Question: Do I have a rootkit? Is that why Win updates and 8.1 would not install successfully (they need to change the boot sector, maybe?


Question: If I scan the laptop at boot time w BDTS rescue disk, will it detect and fix rootkits?


If so, how do I get a rescue disk image w the latest definitions?


Thanks


Aloke