100% disk usage

Probably just disabling (disable in start up) Dell Support Assist would have fixed it.   On some models, there is a Support Assist app that is used in the POST (Power On Self Test) and hardware diagnostics,

Having said that, I have a dual boot (two Win 10 installations) on my Inspiron 15 5577, one with the full Dell image and another without Dell support assist that I use in my recording studio and it works OK.

We need the model number (Inspiron 3501, 3593, etc.) to advise you on the answer.

Update: I've finally decided to bite the bullet and upgrade the laptop from 4GB to 16GB RAM. As expected, some software opens a bit faster, and Task Manager now reports memory usage peaking at about 18% (running one application at a time, usually). However, nothing else has changed. The HDD is often whacked out at 100% with nothing happening (with System, Search, Antimalware or one of the Update possé taking top spot). Sometimes I can hear the HDD clicking away. Sometimes it's silent yet the listing still says 100%. Often it seems to freeze and even Task Manager won't update its display.
Almost every time I start to type into the Taskbar Search box (or Search in an Explorer window), there's a long delay before the system realises what I'm doing and starts displaying the characters. Usually it misses out the first few letters, so I have to go back and re-type them. This is a dysfunctional system.
Given that this has had a "clean" install with only the required device drivers added, I have to conclude that it's either a driver issue, or (more worryingly) there's a hardware problem.
On other forums, I've been advised to replace the HDD with an SSD. I'm sure this will help as if it's genuinely trying to access the drive so much, fitting a much faster SSD will minimise the effect. But at the end of the day, this is just treating the symptoms, not the root cause. My other (older) Dell laptop with only 4GB RAM and a slower HDD runs Win10 with no problems at all.

Update: after a few weeks with 16GB, I can confirm that the issue is exactly the same. It still struggles whenever too many background processes are going (usually Win update services - and there are many of those!). I tried pausing the updates for a couple of weeks but Windows ignores that setting and the updates carry on running anyway. But as I've said before, that's not the real problem. That's just making it worse. The real problem seems to be some driver or hardware issue with the Inspiron itself. It freezes for several minutes (maybe up to an hour) and I just have to walk away and wait. Every couple of weeks it decides that the HDD is at 100% with just the System process using it (but NO SOUNDS COMING FROM THE HDD ITSELF). This suggests either a HDD driver issue or a faulty HDD or interface. My old Latitude (still with only 4GB RAM) has none of these problems and runs fine.

So, Dell: can you come clean, own up to there being a problem with this model and help me fix it? Would another HDD help (it's at least easy to test, once I've bought a replacement)? Or is it an issue with the motherboard and I'll just have to throw this thing away?

Hello

Not sure if your issue was ever fixed, but i was able to find a solution to the 100% disk usage. 

I uninstalled skype.

Immediately, the usage dropped to 2-50% depending on what was going on. 

I did do some other things as well, but uninstalling that program helped a ton, on a win11 machine.

if you have multiple users, each user should uninstall.

I hope this works for you, if not, i dont know what else could. This did work for the machine we were having issues with.

vjpixels is right.  The problem is the harddrives provided with the Inspirons.  They are dead slow.  Just writing this reply has my drive at 100%.  CPU, RAM and Network are all underutilized waiting for the drive to catch up.  A bad choice by Dell repeated for many years.  Cheap but not a bargain.