why not chkdsk c: /f /r ?
because a /r implies /f
do a chkdsk /? for more info
I would do that but will it restore the old MFT? I have an almost empty 250gb external drive available and the disk on this pc is 80GB
Acronis backup will either do a sector by sector backup or a file by file backup. The sector approach will reapply the faulty mft. The file by file skips all metadata including the mft.
Your best approach is to do a file by file backup, do a full format (not quick) and reinstall your windows. Install Acronis and then mount the image from your external drive, copy personal files back to your newly formatted disk. You will unfortunately need to reinstall most of your programs due to missing dll's and registry entries that would only be reapplied by a fresh install.
Theres probably a lot of work for you ahead, you might even choose to skip the task and never see an issue arise. Another way to look at it is you may one day turn on your machine to find it fails to boot due to a faulty mft, and be left with a bigger problem. Either way, backup your files for peace of mind.