XPS 8700, hard disk not working

If Windows 10 is activated on the system at present, you can easily install it again. 

This system has no support for Windows 11 and there are signs at present that Microsoft is planning to soon stop updates for Windows 11 on systems that do not support it (it hasn't yet done that, but has made statements indicating it soon will).

@ejn63​ Thank you. 

Annoyingly, Dell support site does not recognise my tag.  If it did then it would, presumably, be able to recommend a replacement part.  then I can could consider the price against the risks of the computer have a limited useful life.
Are you able to recommend a replacement part, please, or would you advise to buy a new computer?

Any SATA drive will work -- if it's to be the boot drive, a SATA SSD is a far better idea than a spinning hard drive.

Unknown as to why the 11 year old XPS 8700 Service Tag is not showing on the public Dell UK site?

The Dell internal tool shows the private XPS 8700 Service Tag number.

* Shipped from Dell UK on July 26, 2013
* Shipped with G1XNT HDD (1TB, SATA3, 7.2K RPM, 3.5", Seagate Grenada BP)

@DELL-Chris M​ My service TAG (viewable in BIOS) is <removed from public view>.  When searching for it, I get "There is no match for that Service Tag or product ID".

I know. That is why I stated that above. DELL-Chris M

@ejn63​ chatgpt has given me four recommendations but they are all 2.5 so i will need a mounting bracket.  i presume that's not a big deal?

I can get WD Blue SA510 from Amazon for £54.  Mounting is £8.  That should be good enough, yes?  No need for anything else?