A couple years ago, my father made a backup of one of our computers using Windows Backup and Restore. It was either Windows Vista or Windows 7, not sure which. He backed up the entire computer, including Program Files, AppData, My Documents, everything, and now it is on .zip files on a WD Passport with 300GB, I'm not sure exactly what it is called. Now I am trying to decide which files to keep and which to delete. Most of what we would keep are files, as we would need CD's to use the programs, and I'm pretty sure they would install everything all over again. That pretty much leaves out Program Files, however, I'm not sure about AppData. For example, my mother used Greetings Workshop and wants some files from there, and she may want to keep some default settings she used. I am talking generally here, as I'm sure some programs have different ways of saving things in AppData.

What, if anything, should I keep from AppData, and what should I delete?


There's no universal solution to this question. No one will ever give you a comprehensive answer because there are so many applications. Each application stores its preferences differently, and you have to know for each particular application what it stores in AppData to decide whether it's worth saving or not.

Let me give you a couple of examples:

  • Firefox stores its profile and general settings in AppData\Roaming. I think it's worth saving, the browser will be configured the way it was, including bookmarks, and even open tabs will be restored.
    At the same time the data Firefox stores in AppData\Local are useless: there are different caches.
  • Opera browser follows the same approach. You find its generic settings in AppData\Roaming and (mostly) throw-away data in AppData\Local.
    Yet if you used Opera Mail client, all the mails are saved in AppData\Local, thus you may want to keep your mail messages.
  • Microsoft Outlook stores its personal files with mail in AppData\Local.
  • foobar2000 audio player stores its settings and playlists in AppData\Roaming.

Usually data in AppData\Roaming are more important than in AppData\Local.

  • Thank you. I figured it was something like this, with all the programs storing data somewhere else. I just wish there were some standards, or at least that the major companies were more forthcoming about where they keep their data. It would make it easier to transfer to other computers. Ah well. – trysis Aug 24 '13 at 21:00
  • There are recommendations only, and for a long time… By the way, there's also ProgramData where applications store information that should be available for all users of a computer. – Alexey Ivanov Aug 26 '13 at 7:49
  • I'm not sure they have ProgramData on Windows 8, which is my new computer, but I know what you mean. Both are folders you almost never hear about until you're experimenting or need to use them. And when you need to use them, there is not enough guidance or standardization about how. – trysis Aug 26 '13 at 13:17
  • Yes, there's C:\ProgramData in Windows 8 just like in Windows Vista/7. These folders are not for users, they're for programmers. MSDN has guidelines on how to use these folders, what data to store in them, yet not every programmer, not every company follows the guidelines. On the other hand, the situation now is much more better than it was in the Windows XP times. (These guidelines are there since Windows 2000; many ignored them at all assuming every user has administrator rights until Windows Vista has changed the rules dramatically.) – Alexey Ivanov Aug 26 '13 at 17:21
  • I suppose they didn't think about people trying to transfer data directly from computer to computer outside their "approved" methods of transport? Meaning, moving the files in AppData & ProgramData themselves instead of through their programs? – trysis Aug 26 '13 at 21:42

The main reason for your question is the wasted space in your backup so try to search in the AppData folder for all files that are bigger than 10 MB by typing size:>10MB (check for your command if you do not use the english version of Windows) into the search field. Now change the view to details and sort by folder.

By that you should be able to decide on yourself which folder contains important or useless data. Examples of folders containing useless data of considerable size:

  • AppData\Local\Temp\
  • AppData\Local\Microsoft\Windows\
  • AppData\Local\CrashDumps\
  • etc

I never found comparable folders inside of AppData\Roaming\ so it should remain in your backup.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.