Run an ePSA diagnostics and then let me know.

I think that it might be an OS reinstall that will fix your issues but I’d backup your data first.

Hi  Sorry for the slow response.  The forum would not allow me to post a reply for a few days.  I did the ePSA test.  It all came up with green ticks.  The webcam passed its 3 or 4 tests.  I did the test twice.  Once without an external drive and then with a drive.  It did not recognise the external drive and only tested the built-in hard drive.  

What do you think?

Hi @PaulAlienM17x  it is very odd that the 17 R2 drivers appear to have disappeared. This could be a win10 update error and Restore to an earlier date when drivers were working, might fix this problem. SupportAssist is not listed in Support for Alienware 17 R2 Drivers & Downloads, but users are encouraged to download SupportAssist from Dell SupportAssist for PCs. The 17 R2 Diagnostics provides trouble shooting tests. Try Custom Component Test - Other, to test USB and Removable Storage. Hopefully these support options will restore your 17 R2 drivers. 

Hi
A windows update did not change anything. To add to my joy the Component Diagnostics test does not get beyond the "gathering information" stage. It just keeps gathering seemingly indefinitely. I looked at Restore but I had not allocated enough space. Only one restore was available and that was after the problem began. I tried a USM mouse today and that does not work either. It was fine a few weeks ago. Something is causing the PC not to look at all the USB inputs. The Dell ePSA (was that the acronym?) did show 3/4 tests on the integrated USB webcam as being fine. I have done a Win10 update and a BIOS update. Oddly though after the latter and a restart the list of potential updates still had the BIOS one as outstanding.

Hi @PaulAlienM17x  thank you for sharing an update.

This behaviour suggests that the Operating System has not been fully loaded during start-up because either your C drive is full or failing. Postulate that drivers are not being fully loaded because there is very little free space on the C drive.

The 17 R2 needs free space into which the operating system expands into during start-up. If the C drive has very little free space, the operating system does not fully load, but still attempts to start none-the-less. This smaller operating system will not have all the drivers that the full operating system would normally provide. 

Open This PC and either hover cursor over the C drive or right click and open its properties. Is there application software that is not required and/or can be removed? Is the storage drive(s) shown and is it possible to move some of your personal files from the C drive and onto the storage drive? 

This is normally the time for the cloned stand-by C drive, that was created earlier as part of disaster recovery, to be swapped-in to get the 17 R2 fully operational. 

Please share an update on what you find. Thank you. 

Hi

Thanks for the suggestion. I have 463Gb free space on the hard drive.  I don't do any graphics intensive work and the free space has been relatively stable for years.  I cannot see that the free space is a constraint.

Hi @PaulAlienM17x  thank you for sharing an update. Agree, there is more than sufficient free space on the C drive for the full version of the Operating System to occupy. Have a look at what the Operating System is saying in the Event Viewer. It should have detected and provided a error code for this problem. Unfortunately Microsoft error codes are usually obscure, so use the internet to find your problem with this error code and hopefully see their solution to fix this systems problem. For example: USB ports not working. error code 0x800F0219 and 0x800705B3. 

Hi

Thanks again.  I do appreciate your help.  I have never used Event Viewer.  I cannot see a heading or sub-heading for "Operating System".  There are so many options and trawling through them has thrown up 60k+ events of various types, mostly similar ones that repeat.  Can you guide me to exactly where I need to look in Event Viewer for this situation please?