Hello I have been reading the posts here and I elaize that most part of the people that comes here does not know that to learn something the fisrt step is to read the manual.
So here is something to help thouse that do not like to read.

Now in MHDD you can press F1 to see list of commands.

For example, you can type "scan" and press enter to begin the scan.

During the scan/read/copy you will have this visual:

- Usual gray boxes means OK blocks
- Green boxes usually means OK too
- Brown and Red boxes means that there is small delay; drive becomes unstable in that place.

- The simbol "?" means timeout, drive hanged. Usually you need to re-power drive when you see this. Also this drive is very unstable and probably will die very soon.

All symbols below boxes and question are errors (bad blocks)
- x - means UNC error - usual bad block (software or hardware)
- S - means Sector ID not found. Usually means firmware (defect lists/translator) damage
- A - means Address Mark not found. Usually means problems with sector headers/format problems
- ! - means command aborted. Serious problem with heads/system area, or scratches on the media

Another symbols can appears rarely and will means serious damage.

Maybe this can help.