It's almost certain that the reason your hard disk is at 100%, is because of the abundance of processes running.
It's clear to me that you don't know which ones to stop and possibly don't know where to stop them, otherwise, you would have already done so.
This means 2 things.
1) You need to get yourself into a functional environment, ie: safe Mode.
2) You have to take screenshots of these unwanted processes.
To start with, Win 8 is different from previous systems in that it doesn't allow you to use the F8 key at boot up to get into safe mode.
Instead, you have to bring out the Charms bar, hit "Settings", then on the subsequent charms bar, hit "PC Settings" (at the bottom).
That will open a full screen page that has a recovery option.
Hit that, then hit "Restart now" below "Advanced Start up.
Your computer will take you to a blue screen where you will choose an option called "Troubleshoot".
On the next page, hit "Advanced Options".
On the following page, hit "Startup Settings".
Then hit restart on the following page.
The computer will then give you a page offering a variety of options by number.
You should choose #5 by typing "5", at which point the machine will reboot into Safe mode.
I know it all sounds convoluted, just to get into Safe Mode, but if you have a Win 8.1 machine, the step by step instructions above will get you there in minutes. If you have a Win 8 machine, the instructions are a wee bit different, but similar enough to figure it out along the way.
Now your computer should function well, as it won't have all those extra processes running.
Posting screenshots of the processes will do us no good now, as none of the unwanted ones are running, so we are going elsewhere to get the list.
Open the Control Panel and go to "Administrative Tools", then hit "Services" (double click).
When the Services page opens, make it full screen and then hit the "Startup Type" heading, so as to have all the "Automatic" options at the top.
In other words, you're sorting the processes by the order of them being told to start automatically.
At this point, take screenshots of all of the processes that are in "Automatic".
We're almost done now.
Open the Task Manger and hit the "Startup" heading and take screenshots of that too.
Once I/we have those screenshots, it'll be a simple job to tell you which ones to turn off and at the next reboot, you should be A OK.
If this is all too much, just say so.
There's always a plan B if necessary.
All is well in Paradise.