How do I edit my hard disk partitions?

[CyberDevil]

Hello.
I got a Lenovo laptop that came with Win 10 10240 pre-installed. The product key is probably stored somewhere in the ROM (Isn't that the case with most modern laptops?). The OS drive is like 900 GB and the other drive is around 30.
So here's the question. What if my get an ISO image of Win 10 10240 from MS and reinstall Windows completely sizing the partitions how I like? I would like the OS partition around a 100GB and another partition with the most I can get out of my 1TB HDD. If I do install Win 10 from an external flash drive and size the partitions how I want, will Windows automatically detect the product key and activate itself?
The OEM Recovery drive will probably be wiped out, so can I still use the Windows reset feature to get it to the state that I made when fresh installing Win?

 

[CyberDevil]

I forgot to mention that the Windows Disk Management utility only allows me to shrink the volume of the OS partition to half its size.

 

[Colif]

Does laptop have a 32gb ssd and a 1tb hdd or just a 930gb hdd?

download the Windows 10 media creation tool and use it to make a win 10 installer on USB

You don't need the product key or use version 10240. Just install the current version and when you reach part of installer asking for key, click "I don't have a key" and win 10 should auto activate itself. when win 10 was first activated on PC it would have added a record on a Microsoft server saying that the laptop is eligible for a win 10 install

Win 10 will create 4 partitions when it installs but you can probably create an additional 800+ gb partition during the custom install process (see step 13 here: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html)

 

[CyberDevil]

1 TB HDD with about 910 GB available to me

 

[Colif]

You will get that additional 30gb back give or take a few 100 mb for the 3 additional partitions windows creates

 

[CyberDevil]

What do you mean version? The Home Edition that I'm using?

 

[CyberDevil]

So if I download the Windows Media Creation tool and then download the latest build of Windows Home Edition and install it, I'm good to go, right?

 

[Colif]

version = latest build of windows 10.

Second question: You should be,