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Discussion Starter #1
Hey all! I hope for this to help someone out there in Internet Land. There may even be useful info here for expert Windows users. I'm sure someone else can contribute more useful info than I have.
About me: I'm a computer technician by occupation, and I love the OCN.

As you probably know, chkdsk.exe (Check Disk) is and has been the Microsoft Windows disk checker for a long time now, since it replaced ScanDisk in Windows 98 or so.
  • It is used to find and correct NTFS file system errors (using chkdsk /f
  • It can also be used to test the entire "surface" or writable area of the disk (both HDD and SSD) for read/write errors (bad sectors) using chkdsk /r.
  • Examples of proper command line syntax are chkdsk /f c: and chkdsk /r d:
  • Chkdsk can't check your system (C:) drive while Windows is booted, so it has to run at system startup to check C:.
  • Chkdsk can be run from within Windows to check drives other than your system drive, such as a connected USB flash drive, or an internal storage drive other than C:. (This will require administrative permission and must force a dismount of the volume to be checked, which will be inaccessible during the entire duration of the disk check).
  • Chkdsk can only be run using administrative permissions, either from an administrator command prompt, or using the windows UAC "allow" button.
The stages of chkdsk (1-5):Stages 1-3 are the file system portion, and if selected, 4-5 are the entire disk portion. 4-5 are the long part, 5 taking the longest. Here's the Microsoft info page on chkdsk. Here's a Yahoo answer about the 5 stages.

Fixing file system errors: Chkdsk /f c: runs stages 1-3. It is commonly run at Windows startup if manually scheduled by the user, or automatically scheduled by the system due to an "unsafe file system shutdown" (such as with electrical power loss, system crash/failure during hard drive operation (before closing the NTFS filesystem). This is usually pretty quick, even on a 1TB HDD, and just involves checking all of the indexed file locations for "pointer" errors and such (like when the disk's file table has a reference to the wrong physical location on the disk, etc.)

Scanning for bad sectors: chkdsk /r runs stages 1-5. It can be extremely helpful in finding bad sectors on a disk, but it's not without it's trouble in Windows 7.
  • It can take an incredible length of time to complete (days for Terabytes of disk space) especially on an HDD with a lot of data recorded to it.
  • For new HDD and SSD, it is important to test the entire disk for bad sectors, so that you know you didn't receive a defective product. It's probably much faster (than CHKDSK /R) to instead, do a "complete format" (which tests for bad sectors) instead of a "quick format" which merely writes/re-writes the file table (in which case you just hope there are no bad sectors). Whereas, an HDD that already has data recorded, chkdsk then has to *****foot around the user's existing data so as not to cause any data loss (involves temporarily relocating the data, and the writing/reading the sectors, and then finally returning the data to the sectors where it was found, before proceeding onward. It's an arduous process.
  • exclamation.gif
    There are no guarantees in life. Back up your data before running chkdsk. Yep. Don't say I didn't warn you. Spontaneous disk failure can happen, or even data loss due to other system malfunction.
  • Chkdsk probably will ultimately consume almost all of your available system memory (RAM) while it is running in Windows, especially on larger disks.
  • Chkdsk /r inexplicably seems to lock up at times within Windows (even on Stage 1).
  • During one of those infamous lock-ups that chkdsk seems to have when run within Windows, I swear to you, I have hit "Ctrl-C" (control-C) which usually closes applications, but does NOT close Chkdsk.exe, and it seems to unfreeze! Call it whatever you want, but I'd appreciate some testing of this! PLEASE HELP TO CONFIRM THIS TIP BY REPLYING WITH YOUR OWN RESULTS.
  • I seem to have better luck while running chkdsk from within Windows PowerShell instead of regular old cmd.exe command prompt.
  • Want to interrupt chkdsk because it is taking too long? You should just let it complete, but if you need to stop it within windows, just close the console window or kill the chkdsk.exe process within task manager (ctrl-shift-esc).

For scanning NTFS drives and partitions, unfortunately I don't know of a better disk utility (I'm sure there is one). Any suggestions, and is it free or paid software, and does it run faster? I'll add them here. So far, I haven't found a Linux app that can do a decent job with NTFS partition checking. Help! Thanks!

910 Posts
Discussion Starter #2
So terribly annoying: chkdsk seems to pause whenever my computer is locked. Garbage.

I can leave it for hours and it makes zero progress until I return. How useful.

Pictured: Chkdsk acting like a Boo, from Super Mario.
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