Hi,
OK, so W10 works fine, as I expected it would.
You would have to use the W8.1 driver for the SAS controller, as I don't see a W10 driver listed.
What would do to instal this driver is to download and install the free 7-Zip file manager program.
The 2nd one down on the top of the page is for 64 bit.
LSI 2308 SAS Driver - Windows 8.1 64
https://ftp.hp.com/pub/softpaq/sp69001-69500/sp69178.exe
After you install 7-Zip, right click on the driver file you downloaded.
Have 7-zip Extract to: and let it extract the file into its folder name (sp69178).
Once that is done, go to the device manager, click on the SAS Controller device needing the driver.
Click on the driver tab. Click on Update Driver.
Select the Browse my computer for driver software option and browse to the driver folder that 7-Zip created.
Make sure the Include subfolders box is checked and the driver should install. Then restart the PC.
Now, back to the original issue...how to install W7...
From the screenshot you posted...it appears that you have the drive controller set to IDE mode, and
IDE would be the worst possible drive controller setting you can have-performance-wise, according to the service manual (chapter 2, page 44).
RAID + AHCI—Both the RAID and AHCI OPROMs execute. This emulation mode is the default and offers the best performance and highest functionality.
So, before we can proceed with the W7 installation project, see if you can go into the BIOS and change the setting from IDE to RAID + AHCI, restart the PC and see if W10 will boot. I know that if you tried this in W7, it would not, but W10 is more intuitive.
If W10 doesn't boot up with the drive controller setting changed to RAID + AHCI, please reinstall W10 in RAID + AHCI mode.
Then please post the hardware ID's for the SAS controller and the Storage controller listed under the IDE ATA/ATAPI Controllers device manager category. It will now have a new description with the BIOS setting changed, and you should immediately 'see' better drive performance with this setting.