run command prompt as administrator
chkdsk /F /R c:
when it asks to check on reboot go for it (press y, then enter)
Then reboot(maybe save your work first)
The disk check should initially estimate that it might take 2 hours, then for 'reasons' it shrinks rapidly. It goes through 5 stages that you don't have to watch... unless it finds errors and can't fix them. In that case boot from any popular disk repair tool software(usb, cd/dvd, floppy drive) and fix the drive that way.
Good luck.

it got worse, I cant even acess my second disk drive anymore :(

and also thanks

That hard drive failed. The I/O from the Helldivers update was just the straw that broke the camel's hump or whatever.

Make sure cable inside pc is still attched, ( let's say you have moved the pc or been inside it recently, some times own hand can do mistkae when set gear in and effect other cable, most never do such mistake but, i and other have seen own mistake happend before.

You can't have pc's over 40 years and not do a tiny mistake that's almost impossible.


But as above user point out, hard disk burnout or failed is seen before.

You might laugh now, but i recive a free pc , some week ago, no boot drive anymore.

and i had not deal with it in a while, new disk and reinstall OS, suprise suprise, what are the odds a power plug was lose and disk was okay, i mean i dont get it how the hell can such go lose, it most have been broken or last user has done it.

So you see how crazy that is and what are the odds you notice it. ( i only lotice then pole of the plug was not there and cord was lose from power plug... FFS crap happends, i will rather tell you things can happend no matter, and also raise a issue it was running untill it went down, and still dont get any sense how it got lose in the first palce , as i said most have been bad before i recive the pc.

Op could also change steam DL server and validate game files to make sure its not. one of them rare issue with a game devs content isue on that server he current use.

download "crystal disk" and check if both drives are still operational,
also you can do that in disk management, and with diskpart with cmd commands.
the best advice is "check your cables" first.

Could be your hard drive is failing. Corrupted files, alot of them, is a dead giveaway your hard drive is dying. What kind are you using? A HDD or SSD? There are different programs you can use to check they are failing.

Also, magnets are not good for hard drives. Do you have any magnets or things with magnets in them around your hard drives? Also where if your pc tower at? On the floor? If it is, do not do this. It can plug up your heat source fans.