Recently, I was working with a client who had a strange problem. He was trying to copy some files on his computer and ended up getting this odd error message:

Can't read from the source file or disk.

error message

What’s odd is that he could easily play the file in Windows without a problem. It was only an issue when he tried to copy the file. After playing around with it for a while, we tracked down the problem. In this article, I will mention the different reasons why you may get this error message and what you can do about it.

File Size Limits

The first thing you want to look at is how big the file is and where you are copying it to. For example, if your file is a huge 5GB movie file, then you won’t be able to copy it to an external hard drive that is formatted with FAT16. A FAT16 formatted drive can only support up to a 2GB file. FAT32 can only hold up to a 4GB file. Most external hard drives and flash drives are formatted in FAT16 or FAT32. Check out this cool site that breaks each format down for you and the max file sizes:

ntfs vs fat

For whatever reason, when you try to perform a copy like this, you can sometimes get the “Can’t read from source or disk” error message. It doesn’t make much sense, but that’s what happens.

Possible Bad Sectors

If you’re using an external drive, you could possibly have some bad sectors on the hard drive, which is causing the problem. In this case, you should scan the hard drive using a tool like chkdsk. If there are any errors, it will go ahead and fix them. If you hard drive is going bad, then you may have to simply get a new hard drive.

If you’re trying to copy from an external drive to your local computer, then try plugging in the external drive into another computer and see if you get the same error. If so, that means the external drive is probably going bad. It’s a good idea to at this point to use some third-party program to copy the files off forcefully even if they have errors. I have written about a program called TeraCopy, which will copies files even if they are corrupted.

Power and Cables

In a few cases, the issue is related to other hardware factors. If you’re trying to copy to an external hard drive, make sure it’s got enough power. Sometimes if it’s connected to a USB hub or something like that, the drive may not be getting enough power for the writes and therefore it fails.

Also, try switching out the cable you are using to connect the external drive to your computer and see if that makes any difference.

File Name Problems

Another possible reason for the error could be that the file name is something that Windows does not recognize and therefore gives you an error. One example is if the file just ends in a dot, like mytestfile. This can happen if you copied some files from a different operating system like Mac, if it got renamed via the command prompt, etc. Try to rename the file and see if that makes any difference. You may have to go into DOS and rename the file there if you are unable to do so in Windows.

Note that if you are getting this message when you are trying to delete a file instead of copy a file, then you should check out my other post which is directly related to this problem. Basically in Windows 7, you get a Could Not Find This Item error message, which is the same as the can’t read from file or disk error message in XP.

If this did not solve your problem or if you came up with a different solution to solve your issue, post a comment here! Enjoy!