win 2000 would be a good choice on that computer. or xp (with no service packs) if you added 256mb more ram.
AMD Phenom II x6 1045T @ 2.7 Ghz
8GB Corsair Vengeance Ram
Crucial M500 240GB SSD (boot drive)
500GB WD 5000AAKX-001CA0
1.5 TB Seagate ST1500DM003
Zotac Geforce GTX 950 2GB GDDR5
Windows 10 Pro 64 bit