There isn't any real need to create the 100 GB space. If that was created it would push the OS further on the disk, increasing seek times.
Edit - strike this wrong statement:
Additionally, it would be an extended partition with logical drives, not a primary (it would be the 4th part on disk 0 - Recovery, System, Boot, NewPart).
This should be sufficient to resolve the SysRsv issue:
Use MiniTool Partition Wizard to shrink the C: drive (labeled Gateway
Windows 7) partition by 100 GB 400 MB, remove the 100 GB 400 MB from the front of the partition, not the back of it. Add 400 MB (not GB!) to the system partition making it 500 MB total in size. In the remaining empty space, create a primary, NTFS partition. Don't forget to click the Apply button in MiniTool.
Anyway, just curious why you suggest creating that partition, and more to the point, why in front of the Boot (Gateway C:) partition.