As far as I can see HD is with Windows and it should be dual boot !? My experience: Windows makes a 99MB UEFI partition. Solus installs the system but not the Bootloader. I solved this problem by creating a new (second) UEFI partition of 300MB (don't forget to flag it BOOT ESP!) And during installation select that partition for the system (Bootloader).
This is how Solus can be installed, but as a separate system. The BIOS should recognize Solus as a UEFI system and Windows! You can select Windows or Solus in the BIOS, (BIOS see Solus as "UEFI on disk...") or during startup using the "BOOT selection" option (one of the F keys). Integration is possible, (to have a dual boot with the menu), but I would leave that for later! Let's first see if Solus BOOT will work!
So - boot system, (UEFI Solus), start Gparted, select HD or SSD for installation, and delete partition 6 (as I see partition 6 EXT4 82.3GB is not a successful installation of Solus !?). When you do that, use that unused space to first create a new 300MB FAT32 partition, then manage flags, (right-click on that partition). For that partition, select BOOT (ESP is added automatically), and now you can use the rest of the space for one EXT4 partition for Solus! When this is done close Gparted and start the installation. Don't select "install alongside windows" select "something else" and on the next select partition (if you haven't changed anything else on that disk - your svreenshot - it should be: / dev / sd- (something) 7 EXT4 to install linux and proceed. Next select a new UEFI partition to install the bootloader, (should be /dev/sd..(something)6!) This - "/dev/sd..something is" /dev/sdb "or" /dev/sdc "- one of the disks in the computer!
If Solus works properly then we can do the rest of the work to make it work like a real Dual BOOT!