Downloading game of 43 Gigas from Steam,discovered only 36 left on SSD

Hello. Got this gaming machine with W10 just this week. Very confused, looking back fondly to W7. Anyway, I installed the software I'm used to, Firefox, Thunderbird, plus Malwarebytes. Wanted to make room for game being downloaded. Found out I can't delete Microsoft's stuff I don't want to use. So a game from Steam of 43 Gigas is downloading it's slow way onto my machine. But only 36 Gigas free on the SSD C: drive, which is evidently according to Parameters the place for applications. The SSD drive C: (nor the D: drive) shows no sign of augmenting so I assume what has downloaded so far is being cached somewhere, and not so far on the drive. But when all 43 gigas have arrived, will they try to find room on C:? In other words, what's going to happen? Is there anything I can do?
Thanks

Your SSD looks to be 120 GB in size. Which is just big enough to hold your OS an Office suite and a few other programs. Everything else should be stored on your 1TB HDD. This is done in 2 ways....in windows 10, go to settings, system, storage, change where new content is saved.....change all those to your D drive. The other way is in your browser settings...and they're a tad bit different for each browser.

I appear to have been able to get rid of Office, later I will import my own favourite and put it on D: disc. For the moment, isn't it the point of the SSD disc, C:, that programs will run very fast? If so, I would like to put the game on C: Would it be possible for me to move something already on C:, such as malwarebytes or a Windows programme to D:, so as to clear a bit of space?
I have done the new content settings so all goes to D:, except reluctant to do so for applications for the moment so the game goes on C: Thanks for that advice.

I have just noticed I am in the Gaming forum; someone up above must have moved me from Installations. I thought the problem was more of that nature, installing a new programme than about gaming. Right, here I am.

Bottom line is: Your C drive is too small. You can move files back and forth all you want.....but your still left with a C drive that is too small. You will have to get a larger SSD to permanently fix your issue.

Oh. Well I am not going to do that; this machine has already cost me a fortune. I think the game download will have to be suspended for the time being while I try to delete stuff. However, to pursue a question: do applications run faster on C; the D is only a 5400 rotation hard disc?

"isn't it the point of the SSD disc, C:, that programs will run very fast?"

Not really, they will load programs faster but they generally won't run any faster as that is much more the CPU, GPU and the amount of RAM and graphics RAM.

Only if you have a vast amount of data swopping to your SSD will there be a difference, like in a lack of RAM scenario.

With a 120 GB SSD there is not much you can install on that. Large fast SSDs are expensive.
I currently only have 2 largish games installed 60 GB, and the Windows folder is 30 GB plus various windows bits and pieces, that would fill a 120 GB drive.