Really, a surface scan should be done, either utilizing chkdsk, or the manufacturers utility before
deciding the drive is bad. Those look like logical errors to me. Not hard (surface) errors, but errors where the
pointers in the file table and/or other parts critical to NTFS have been corrupted for one reason or another.
I’m beginning to wonder if avast itself, in certain circumstances, trashes the disk, because there have been so many
incidents. In some case, when essexboy has provided a script to “uninstall” avast using FRST, users
PC’s miraculously recover, and other times they do not.
Similar problem happened to me once before, the boot stops at a black screen and goes no further.,
usually on Windows Vista and newer systems.