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Is It Safe to Delete Log Files?

Do I need to keep all of the log files created by Windows Update or any other install/uninstall or system-generated procedure? Will they ever be needed again? I see a lot of them in the Windows folder and as far as I can tell, they’re just text files taking up space.

In general, it’s safe to delete log files, but let’s talk about why we have them first.

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What are log files?

Many different applications and operations on your computer generate log files as diagnostic aids; they help you when something goes wrong.

You can often use Notepad to open and read them. In some applications, you can understand what the log says, but for the most part, the content is pretty meaningless to most, and is really intended for support or technical folks.

The important thing to realize is that you may be removing a source of diagnostic information if something goes wrong later.

If things are working and have been for a while, I’ll delete the files. I’ll do that every once and a while, but most of the time, I just leave them. That’s because they’re scattered all over the place. It’s  not worth my time to find and delete them. They’re also taking up very little space in comparison to the disk size.

When log files are a problem

If you are running into space issues, it may be a log file that is causing the problem. In that case, I might start by running a utility like CCleaner. One of the options that it may give you is to delete all of the log files. If you continue to run into disk space issues then of course it means using additional tools and techniques to diagnose the problem.

The bottom line is that the files are typically just fine as they are. You can delete them if you want, but it’s not worth your time, in my opinion. If you’re worried about losing them, back them up first. Copy the files to a CD or another drive and then delete them on your hard drive.

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14 comments on “Is It Safe to Delete Log Files?”

  1. I never thought of deleting log files to gain space. Just now I check how much space they take over 141 files. It took me one minute to know they take 21MB. In my view it is no use to delete them. I just need to install a larger hard drive.
    Theo

    Reply
    • 2 log files on my system totalled up to ~2.5-3 GB size, I deleted everything in that folder save for cbs.log and freed up ~3.5 GB of space.

      Reply
  2. my C disk is almost full, only less than a gb left. app_RASAPI32 & firefox_RASDLG took space more than 5gb, is it safe to delete both ?

    Reply
  3. Hi, I have 62gb of “com.microsoft.Outlook” log files in my macbook, can any one please clarify these are server file back up in system if delete all these, will i have emails in server. please help to understand stroge management.

    Reply
  4. Hello
    I’m running out of space on my Lenovo Thinkpad and I’ve found a folder that has a ton of SDK logs in it going back to 2014. It says the size of the folder is 208GB!!!!
    Is it safe to delete them?

    Reply
  5. Leo –

    Hi. A scan by CCleaner detected over 115 GB (!) of system temporary files to remove from my Windows 10 version 20H2 computer. According to the description of the over 840,000 files, nearly all are a type of Windows Update .etl file dated Feb. 7, 2021, and most of them are only 136 KB in size. Here’s an example from the CCleaner log, and in nearly all other cases, only the 6 digits before “.etl” differ: C:\Windows\TEMP\_11F8594C-12A1-40E5-94AB-80A2ED57BD2\WindowsUpdate.20210207.194122.704.274896.etl

    (FYI. Two days earlier on Feb. 7, I updated to version 20H2 from version 2004, a very slow update process. More accurately, I should say Windows automatically downloaded and installed 20H2 for me when I was actually trying to install, after repeated failures days earlier, the January 2021 monthly cumulative update KB4598242 for version 2004.)

    My questions I hope you can answer:

    1. Are these .etl files safe to delete? (I hope so as they’re really slowing down my various scans, such as antivirus and CCleaner.)

    2. Are these .etl files supposed to be automatically removed by Windows? (I don’t recall seeing the .etl extension and certainly not so many of them.)

    3. Is the large number and total size of these .etl files probably indicative of a problem with the PC? If so, what should I do?

    Thanks so much.

    Reply
    • I would: BACK UP. Whenever you ask yourself “is it safe to …” the first thing that should come to mind is to back up completely first.
      That being said, this doesn’t surprise me. I would let CCleaner clean ’em after the backup.

      Reply

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