Here is how I prep for an install on HDD or SSD..... I do a long type NTFS format creating a single partiton (for your pic I'd delete both partitions using Disk Management on a functioning workstation, and then create a single partition on which I'd do a long (uncheck "Quick" if the box is checked) NTFS format, basic type). Do MBR type... just the basics here.
Then, I'd put the single-partition freshly formatted HDD (or SSD)in your Z820, boot from the installer DVD, get to the page you show, select that single partition that was created previously, and select Delete. Then select New..... the installer then will ask if you want to allow it to create more than one partition if it needs and this is where you say yes.... it will then create the small important "system reserved" partition, and the big OS partition automatically, and will start the install on to that larger partition.
I've noted these days that the Microsoft update process after the install is done takes multiple hours, and you'll think it is broken. Make sure to let that process run over night, and make sure things are not set to have the workstation go to sleep during that process. Then, the actual download and install needs to go forward, taking more time (but faster).
I don't do RAID, and I only do OS installs now on SSDs.