My Cubase files are not linked to the software

Hi guys,
I’ve had this issue before, but a long time ago. It’s annoying!
I open windows explorer, then I open the music project folder and see all my Cubase files. But they don’t have the CUBASE ICON - it’s as if they’ve lost their link to Cubase!
How do I restore the links between files and programmes? I haven’t knowingly done anything to my PC.
This issue is slowing my PC down, making saving my work 5 times longer every time I press Ctl S!!!
I can open the files from within Cubase, but the files remain ICON-LESS, as do other files too…

Thanks v much,

Google “windows file association”?

Tried that - it’s a more complex situation. The whole disk seems unstable… Some folders won’t even open, some other folders take 5 mins to open…
I don’t know how it happened, nor what to do next!

Aha. The hard disk has died. It’s being replaced by a solid state drive.
This should solve it!