I am using Win XP Home SP3. I normally leave my computer on 24/7 I use AVG antivirus (Free) and Zonealarm Pro and am on ADSL. I have begun encountering the following message when I look at my machine in the morning "Windows was unable to save all data for the file \Device\Hard drive Vol1\$UsnJrnl:$J The data has been lost. This error may be caused by a failure of your computer hardware or the network connection. Please try to save the file elsewhere." The machine is sometimes frozen and I need to do a hot boot to restart. Sometimes it does an automatic DisKchK usually shows no errors just restarts. Today showed "Deleting orphaned file record Segment 245289" Once restarted the machine works perfectly with no hiccups. I have a full backup (Acronis) on an external HDD from prior to this message appearing just in case. Does anyone have any ideas what the error message may be warning me of and what I should do? Many thanks in anticipation. I am a long term user but have little experience with "computer speak"

Could be a bad hard drive

Well hopefully that's it with the error messages thanks to checkdisk. This isn't caused by a bad hard drive, it's caused when the device that's having data written on it is stopped unexpectedly, such as your computer being cut from power or a device that's been removed or forced to dismount while data is still being written on it. When this happens corruption of the files you have moved usually occurs and sometimes other files are affected.

What hard drive was stopped unexpectedly to cause this error? Was it your main C:\ drive or something else? What device was writing to the hard drive?

This post has been edited by Davonator: Jul 2 2009, 09:49 PM

Thanks for the responses. I can only assume it was the main C:\ drive. I have a second drive which contains Linux with optional boot at start-up. The only thing which I would expect to be writing to the disk during the night is AVG doing a scheduled scan or Zonealarm. I also have Mailwasher which automatically checks for emails every 5 minutes.
Does this help?

Not really . Everything you've said is all on one disk. You have Linux booting up on a different partition but it's still on the same disk and it wouldn't even be doing anything anyway since Linux wasn't running. Any program running off you C:\ drive is already on the C:\ drive, it would be difficult for an error to be produced by something like this, it's more likely a problem that your system encountered when writing to \Device\Hard drive Vol1\$UsnJrnl:$J.

There's really nothing we can do now since it's going to be difficult pinpointing the problem but your computer seems to have repaired itself and you shouldn't concern yourself with it until it happens again.

Just so you know that $UsnJrnl (USN Journal) is usually hidden from the Windows API (Application Programming Interface), this feature provides a persistent log of all changes made to files on the volume. From what I know of, this is usually only written and read by the system.