How Long is Too Long Before a File is Unrecoverable?

Can I Undelete Files That Were Deleted a Long Time Ago?

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Can you use a data recovery program to recover files that you deleted a long time ago?

Is there some sort of hard rule, like files deleted over one year ago are gone forever?

How do you know if a file has been gone for so long that it's really gone?

The following question is one of many you'll see in my File Recovery FAQ:

"How long is too long before a file I've deleted becomes unrecoverable?"

Technically, it's not a how long question so much as it's a how much data have you written to the media since deleting the file question.

As I discussed in Will a Data Recovery Program Undelete Anything Ever Deleted?, when you delete a file, you don't really remove the data, only the directions to it. The space occupied by that data is marked as free and will eventually be overwritten.

The key, then, is to minimize the writing of data to the drive that contains the deleted file.

In other words, the less writing activity (saving files, installing software, etc.) on the drive, the longer, in general, the deleted files on that drive will be able to be recovered.

For example, if you delete a saved video and then promptly turn off your computer and leave it off for three years, you could theoretically turn the computer back on, run a file recovery program, and completely restore that file. This is because very little data has had a chance to have been written to the drive, potentially overwriting the video.

In a more realistic example, let's say you delete a saved video.

For weeks, or even just days, you use your computer normally, downloading more videos, editing some photos, etc. Depending on things like how big the drive you're working from is, the amount of data you're writing to the drive, and how big the video you deleted is, chances are it won't be recoverable.

In general, the larger a file is, the shorter time frame you have to undelete it. This is because the parts of a larger file are spread over a larger swath of your physical drive, increasing the likelihood of part of the file being overwritten.

See Should I Use a File Recovery Tool's Portable or Installable Option? for help avoiding the most devastating, and ironic, thing you can do when trying to recover deleted files.