A dirty drive isn’t what you think, but it is something you’ll want to clean up.
While they should be avoided, dirty disks happen for a variety of reasons. Fortunately, there’s a quick and relatively easy way to clean them up.
Our friend CHKDSK.
Become a Patron of Ask Leo! and go ad-free!
Cleaning a 'Dirty' drive
A disk drive can be marked as “dirty” if the system it was connected to wasn’t shut down properly. To clean and repair the problem, run CHKDSK on the drive. To avoid the problem, always use the Start menu to start the shutdown process so that your system shuts down cleanly.
What’s a dirty drive?
A dirty drive (which has nothing to do with illicit materials, by the way) simply means what you described: the operating system could not write everything to the drive before the system was shut down. Without those last updates, the drive is marked as dirty.
It’s caused by exactly what you described: losing power without shutting down the system properly.
The only way to avoid this is not to let that happen.
Don’t let the battery drain to the point where the machine shuts itself down. Plug it in or shut it down yourself manually. That means using the Start menu to start the shutdown process. Part of that process will be to mark the drive as being clean before power is removed from the system.
There’s no other way.
You must shut down the system cleanly.
Checking the disk
When a disk is marked as dirty, CHKDSK is the answer.
I’m surprised that CHKDSK directed you to system restore. That’s normally not what happens.
I definitely recommend against relying on System Restore for just about anything. I’ve got an article on the topic: Why I Don’t Like System Restore.
It’s possible CHKDSK might tell you that it is unable to check-disk the drive because it’s in use. This is common if the drive in question is your system or “C:” drive. It should ask if you would like to schedule the CHKDSK to happen the next time you boot up. The correct answer in this situation is yes, after which you reboot your machine.
When your machine reboots, CHKDSK will run and fix the dirty drive.
Do this
Allowing this to happen puts you at risk of data loss. Important data may not have been written to the disk. In the worst case scenario, everything on the disk could be lost.
Make sure you shut down your system by using the Start menu to start the shutdown process.
For a laptop, don’t run the battery down until the laptop dies. For a desktop, consider a UPS (Uninterruptible Power Supply), especially if you’re in an area prone to unexpected power failures. It should give you enough time to shut the system down cleanly when the power dies.
Subscribe to Confident Computing! Less frustration and more confidence, solutions, answers, and tips in your inbox every week.
Podcast audio
Related Video
Keep your computer backed up. When (not if) your computer crashes causing a loss of data, it can be restored with a system backup.
I receive other newsletters but this is the first time one that discussed CHKDSK. Should I run CHKDSK on a SSD and conventual external hard drives too?
CHKDSK can be run safely on either SSDs or HDDs.
I have a process for shutting down.
1. I close all tabs in Explorer except one and whatever is on that tab (usually Gmail) I’ll have signed out.
2. Using the ‘hamburger’ (those three bars or dots in the top RH corner) I select ‘History’
3. When it has identified all history, I close the remaining tab.
4. Using Ctrl + A, I select them all and then hit ‘delete’ and subsequently ‘Remove’
5. Then I run Ccleaner, professional – all the way through.
6. Only then will I either put the laptop in ‘Sleep’ mode or by using the’Start’ button, select ‘Shut down’
7. I now have a clean machine!
I’m not sure you fully answered the question. The reader stated that when they run CHKDSK they get a message referring them to System Restore. You said they should get a message about running CHKDSK at the next boot and how to respond to that. But what if they’re really not getting the message? Is there another way to force CHKDSK to run at the next boot?
You can run the command line version in an administrative Command Prompt, or by right-clicking on the drive in Windows File Explorer and selecting “Properties” and clicking the “Tools” tab. Under “Error checking,” click on Check.
Yes, I felt that there was a deeper problem here. There are several forum questions on the web along similar lines.
An article on the Easeus site says that disk checking may be barred because the disk has become write protected. Some simple steps can be taken to correct this unless the disk is corrupted, in which case files can be recovered through a suitable program before reformatting the disk.
It appears that the original question is not clear in what exactly occurred and in what order. For example, as Leo said, CHKDSK doesn’t ask you to do a System Restore. Attributing the problem to a bad or sudden shutdown doesn’t make sense either because this is not how Windows typically behaves. If a bad shutdown occurs, on the next reboot you get a message asking if you want to do a recovery. A recovery is rarely needed and you can start Windows normally and all will be well. That’s been true since Windows 3.1.
Next, the term “dirty” can be associated with at least two situations. One is if Windows is writing to disk and the process is interrupted. This typically happens with an external drive and not the C: drive. If it happens with the C: drive then there must be problem with the drive connection in the computer. The other situation is caused by CHKDSK itself and it’s about the “dirty bit”, which will prevent you from accessing the drive until the dirty bit is cleared.
Leo has had at least two previous articles on CHKDSK and in there I have comments describing the “dirty bit” (or Google it).
The AskLeo articles were entitled
“Chkdsk Cannot Run Because the Volume Is in Use by Another Process” and
“What’s the Difference Between CHKDSK /F and CHKDSK /R”.
An external disk and an internal disk have similar rates of a interrupted writes. It might happen a little more to an external disk because it relies on USB and if you disconnect a drive without doing a “Safely Remove”, it risks not writing everything. It can be caused by a drive connection problem, but it can be caused by software errors, either a software bug or closing a program prematurely, which I believe are the more common causes of write failure. CHKDSK doesn’t cause a dirty disk. It will report that the disk is dirty which causes some people to think CHKDSK caused the error.
Mark Jacobs: Look up “dirty bit” in connection with CHKDSK. It’s a real and distinct thing with the word “dirty” associated within (by Microsoft).
hi, i have a problem that what is saying its dirty is my external drive D:
what can i do to make it run the check? does running the check on C: also goes to D:?
Run CHKDSK on D:. (Running on C: runs it ONLY on C:)