The pc is about 8 years old and still ran things ok untill windows 10 started playing funny buggars about a month back so tried a repair, bad bad bad move should have known better after all these years. Being that old the bios can only boot from cd/dvd or hd.
Ran Gparted (live cd) booted fine from that, found all the partitions etc and even told me that I needed to run chkdsk /f
BUT it didn't tell me just how to do that when the pc won't boot into windows or from a windows cd/dvd
Firstly, be very careful using GParted. You can easily make any rescueable data gone completely if you aren't careful.
OK, can you dismiss the prompt and use the other functions in Gparted? If so, you could try this:
https://gparted.org/display-doc.php%3Fname%3Dhelp-manual#gparted-attempt-data-rescueFailing that, there are a number of other live boot CD isos that have Data Rescue apps/progs on them. They mainly use a Linux distro of some type.
https://techtalk.gfi.com/top-5-free-rescue-discs-for-your-sys-admin-toolkit/Haven't tried this, but maybe OK:
https://www.lazesoft.com/lazesoft-data-recovery.htmlThey all have their own funny quirks, so read up well before you do anything to the HDD. Again it is easy to make any data gone forever.
Also, depending on the size of the drive, the amount of data, and the reason it's unaccessible, it can take a very long time to scan the disk.
Personally, I'd try rescueing data before trying any boot recovery, or partition recovery. And make sure you direct the recovery to an external USB drive of some sort, not the drive in question. So you'll need a large size external drive.