Strange drivers & Maximum shrink is too big !!

Hello,

I've a new laptop runs windows 8, and now updated to windows 8.1

I want to partition my 1 Terabyte Hard Drive.

I've 2 questions:

1- Maximum allowed shrinking was only 580.88 GB, I wonder why, while windows only need at maximum 20-30GB to run? I need to make it only around 100-200 GB at maximum.

2- I found lots of strange new drivers called "healthy recovery, EFI, OEM". I wonder why they are exist and how to get rid of them to maximize hard drive usage?

Here are the 5 screen shots for what I think it can help in this situation.

http://postimg.org/image/y27m4rtd3/

http://postimg.org/image/62b53ajev/

http://postimg.org/image/w3l0bb8nh/

http://postimg.org/image/60pxxccfz/

http://postimg.org/image/dgfab5wch/

Please advice me what to do.

Thanks.

Regards..