Lollipop on Samsung Galaxy S5 G900H

I'm new to Android (from Blackberry ... I know, quite an upgrade). I want to upgrade my new S5 H-variant to Lollipop. I do not really NEED root (yet) but I'm interested in doing it. I would like not to void my warranty in an obvious way if it can be helped i.e. Knox warranty e-fuse/flag.

I HAVE:

• Model: Samsung Galaxy S5 G900H (International Exynos Octa-core model)


• Android version: 4.4.2


• Baseband version: G900HXXU1ANH1


• Kernel version: 3.10.9-2417570


• Root: No


• Knox Warranty flag: 0


• Factory reset: Recently performed

I WANT:

• Android version: 5.0 Lollipop (preferably lacking as much bloatware as possible)


• Root: Maybe


• Knox Warranty flag: 0 (if possible but not 100% necessary)

I have tried following this guide, on 2 different Windows 7 machines, with Odin 3.7 and Odin 3.9, with different USB cables - the Samsung one, an HTC one, and a USB 3.0 one.

I have also tried using towelroot to root it first, and installed and ran it fine, but it informed me that my phone is not supported when I tried to "make it ra1n".

My biggest stumbling block is that Odin does not pick up the phone when it is in Download (or Bootloader) mode. It comes up as "Added" when the phone is on normally. It seems like the most likely thing is that my drivers are wrong, but I have tried installing Kies on the one machine (which supposedly comes with the correct drivers) and I have tried installing the drivers manually on the other, Kies-less machine. I then swapped machines.

I apologise I'm too noob to be able to extrapolate from current answers how to upgrade my particular model. Can anyone help?