I've just STARTED using my new rig with Windows 10. I'm coming from a Windows 7 Pro PC so I'm still getting used to the new interface. I'm setting my PC to save my data on a SEPARATE D: drive. But what about new apps. Is it suggested to save those on the C: Drive with the OS files?Mostly it's a personal preference but I install all my apps to the C: drive for several REASONS. First of all, my C: drive is an SSD (D: is a spinner) so my apps will load faster. Also, even if you install apps on the D: drive, some of the required files for the app will still be installed on the C: drive. There will also be registry entries made (registry exists on C:). That means that your apps are actually installed spread across 2 drives. I would rather have the apps contained on a single drive. As strollin said, personal preference. PERSONALLY, I have multiple partitions on all of my systems and try to keep C: drive only for the OS, my AV, and ONE or two other "key" apps. Everything else is installed on other partitions. I prefer to keep they system partition as small as possible. But hey, that's me - there is little if any advantage to one way or the other.