Gallery: Inspect hidden data

Whenever you create a file, whether text or an image, your PC generates information about it. This is metadata in its most basic form. To see this information, right-click on a file - any one will do - and choose Properties. In our example screenshot, the metadata from this Microsoft Word file shows the document type, its creation date and information about when it was most recently accessed and modified. The title of the document is also displayed and you can find more information by flicking through the other tabs in the dialogue box

Still in this Properties dialogue box, click on the Summary tab followed by the Advanced button (Vista users should just click on the Details tab). The additional information available here includes the word count, character count, authors and number of revisions. Note that in our example the name listed alongside the Author field isn’t the same as that next to the ‘Last saved by’ entry. This is most likely because the document was based on a template, or is a modification of an earlier document. It’s worth knowing that this author information can be misleading. For example, if a designer created a layout in Word and then you used their file to write a new document, their name may still appear as the original author

The author and company information seen in this screenshot are derived directly from the registration information supplied when Microsoft Office was installed. This too can be misleading. If someone uses your computer to write a letter, your name will appear in the Author field. Although dates and times are taken from the computer’s calendar, this information can be falsified by changing the clock and, prior to Windows XP, the clock wasn’t synchronised via the internet so it was inaccurate. The point is to remember that metadata should always be treated with caution

In this screenshot the Excel file appears to have been created after it was last modified. This is impossible. So what’s happened? We copied a file back to our test PC from a backup. As far as our computer is concerned the file was created at the time we copied it to the hard disk. However the file retains information about when it was last modified - information that happens to be accurate. Similarly files downloaded from the internet carry a creation date matching when you downloaded them rather than when they were generated

Picture files provide a huge amount of information in their metadata. The General tab contains the usual information about the file type and the amount of space it takes up on the hard disk. There’s also the date and time of creation, modification and when it was last accessed. However, click on the Summary or Details tab and you can see the dimensions of the image in pixels, the resolution at which it was captured and even information about the camera used to take the picture. Music files show album, composer and track information

Use the Summary or Details tab to edit metadata. Click in one of the fields shown and enter new text or change what’s there. Note that some of the information, such as dates and file sizes, cannot be changed. If you want to remove personal information from a file’s metadata in Vista, select the Details tab and click on Remove Properties and Personal Information. Now select the details you wish to remove or create a copy of the file with no personal metadata assigned to it

Use the Summary or Details tab to edit metadata. Click in one of the fields shown and enter new text or change what’s there. Note that some of the information, such as dates and file sizes, cannot be changed. If you want to remove personal information from a file’s metadata in Vista, select the Details tab and click on Remove Properties and Personal Information. Now select the details you wish to remove or create a copy of the file with no personal metadata assigned to it