Imminent System Disk Crash. What To Do?

I have a win10 system with a two tera system disk that I think is about to crash.
It makes periodic 'speed up' sounds. Like it has suddenly gone into overdrive. Quite noisy. Like loudly rushing wind or something.

Only lasts for a second or two and then it lapses back into its quiet humming.

I have a drive on there with about 150 G free.

I've been advised in the past and have tried to use Macrium free edition but unless I've clumsily failed to understand and use it properly it hasn't offered me anything else but virtually copy the whole system disk which I don't have room to do.

Which means: there's no macrium backup to look at.

And similarly I've tried restore points in Windows previously and other Windows tricks for this eventuality and they've all failed me when it came to it.

So this time I thought I might jump in before it actually happens and canvass the best advice on how to proceed from right here, now, when it hasn't happened but it sure looks like it will.

Version: i don't know. It's win10 and right up to date I think.

Only about 150 G available space. On a USB drive.

What should I do?

p.s. I should make clear I'm not worried about the two tera of data on the system disk as such. In my experience we can nearly always recover data.

The main object is to maintain a running Win10 installation with all the installed programmes still there.
i.e. the system itself. As I see 'the system', meaning, I suppose 'my system' rather than the bare bones Windows10
system which is what i keep getting driven back to.

Job is 'how to maintain my system'. Funny you never see it said like that isn't it? But that's what we all want to do. Maintain our systems. Hmmm.. anyway.... ?

and a p.s. : yes, I think it's going to be a disk crash rather than a windows crash but I'm not 100% on that. I've known this disk speedup thing occur in both cases - when windows was going wonky and also when disk surface was getting flaky...

Yes, the problem is that I have only 150G free and the system disk, a 2T disk, is nearly full.

I don't have room for a full system backup as I think they are usually presented.

i.e. Macrium, I think, will want more than 150G.

I think Windows backup will want to image the whole disk or something, will also want too much.

Am I wrong to think a backup could be made of simply 'the system' - i.e. the windows installation and all installed programmes - that doesn't include downloaded stuff, self manufactured stuff, data created by apps and so on and that is therefore much smaller than the occupied size of the system disk?

Is that simply not possible? Or if it is, what will do it?

Apart from that it seems to me rolling back to a prior stable time is the best thing. What do they call that - a 'restore point' or something?

I have tried to make them a few times in the past and it never worked for me when time came to look for them. God knows why.

But if there's no better ideas and if those restore points are supposed to work then I think perhaps making a restore point would be the first step right now, wouldn't it?

And then if it is a software issue rolling back to before it happens should work?
And if it turns out to be a hardware issue then the system will restore onto undamaged portions of the disk and that should work, too?

In your case, I would start over from scratch. You need to separate your Windows, apps and programs from the nearly 2 TB of data. I would get a 128 GB SSD for a fresh install of Windows 10 and another 2 TB drive to start transferring your data off the drive you think is failing.

That being said, it does not sound like something a hard disk would be doing. It sounds like something a system fan would be doing. The suggestion to do a check of the drive with software was a good one.

Consider:

Backing up any important files to the cloud > Backing up drivers > Test / replace the drive as needed > Clean install Windows 10 20H2 > Restore drivers > Reinstall applications > Restore files

not too long, I think. It lives with the cover off. Bit of dust on the fan there on the leading edges.

Disconnect one fan at a time until you find the culprit.
If it is the cpu fan for example,then you need to monitor the temperature to see if it is exceeding specifications.
Also check all fans for any speed controls,some newer fans can have automatic speed control as standard.
If it is temp related,perhaps you could consider using a small fan at the open side as an optional extra.