View Full Version : OT - CRC Error

Ian B
05-31-2012, 01:24 PM

I have an external 1.5Tb USB hard disk. When trying to access most of the files, I get a "bad CRC error.

I tried running chkdsk, it gets as far as 19% and hangs - it won't go beyond that. No nasty noises - it seems ok mechanically.

Some files are readable, and I've transferred those to another disk. Anyone know of any good (preferably free) software to recover whatever's recoverable?



Jaakko Fagerlund
05-31-2012, 03:06 PM
Have uyou tested the disc directly in a computer or accessed it through the USB convertor? I would suggest prying out the box open and installing the HDD directly to your 'puter for checks/recovery.

05-31-2012, 03:41 PM
Google search may answer your questions. See: http://ask-leo.com/how_do_i_fix_a_cyclic_redundancy_check_error_when_ i_try_to_copy_a_file.html/


05-31-2012, 05:11 PM
dd, a unix utility, is the best free option for getting data off a dying disk IME. dd for windows (http://www.chrysocome.net/dd) may work as well, though I have no experience with it, or get a linux LiveCD (boots from any PC without altering your Windows install). Once you get the image of the disk you can either dd it back to a new device, or just mount it and pull the files you want off of it. Note that if you have corrupted data it won't get it back - it'll only pull what's available.

Check out http://d.goodlad.net/articles/the_dying_disks_best_friend/ for an example of how it can be used, or google "dd disk recovery".

Note that depending on how your drive has failed any attempts to access it will likely result in some more data corruption, so pull the data as fast as you can.

06-01-2012, 09:06 PM
If I recall correctly, CRC is a "cyclic redundancy check" to check whether a file is correct or not.


http://www.google.com.au/#hl=en&rlz=1W1IRFC_enAU360&sclient=psy-ab&q=cyclic+redundancy+check+hard+drive&rlz=1W1IRFC_enAU360&oq=cyclic+redundancy+&aq=3&aqi=g4&aql=&gs_l=hp.1.3.0l4. 0.0.9ZuN4MNiIVQ&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=ab6ab5064522d809&biw=1280&bih=545

Ian B
06-03-2012, 06:43 AM
Fixed it!

I found a really handy piece of freeware:


It's been running for 3 days now, and so far has recovered 163,000 files, about 750Gb to another external hard disk, almost done. Only 29 files are corrupt - the rest are fine.

They have some other utilities on their site - if they work as well as their file copier, they're worth a look.