How is SSD & HDD space used

[flysplat]

I'm just installing software onto my new laptop.

It has a 128gb SSD & 1tb HDD. At the moment everything is being installed onto the SSD?

Does Windows 10 automatically allocate data to the HDD at some point or do I have to somehow direct it to save to the HDD?

Thanks

[WAWood]

@flysplat 

You're dealing with two different sets of defaults -- applications and downloads.

In terms of the first, applications, those are automatically installed in the SSD -- because the directories most often used, and the Registry collection, reside in the filesystem on the SSD.  In some cases, when you install an app yourself, it will give you a choice as to where to install it, and in those cases, you can direct some of the files to the HDD.  But the Registry collection is always going to reside on the SSD -- so you can't actually MOVE apps to the HDD.

In terms of the second, downloads, those are saved by default in the SSD in your profile folder.  Using each of the Browsers, you can change the default save directory to the HDD and then, in future, stuff you download via Browsers would be directed to the HDD instead of the SSD.