AAAS’s Kate Travis mentioned on Facebook that she was thinking of making the leap to Windows 7 and was advised, by me and others, that she should backup all her data and do a full clean install of the operating system. But, it’s that phrase “backup all your data” that can cause problems and if you reformat a drive prior to upgrading you might discover that there were a few data files that you missed in the backup.

So, what files could they be?

Well, the first and obvious folder to backup is “My Documents” that should be where all you main files are stored, unless of you changed that location. But, if you changed it, you probably know enough to be a regular backer-upperer anyway. Then there’s My Webs, My Pictures, My eBooks, My Music. Double check that your iTunes library and files are all in that last folder. If they’re not you’ll have to locate them and back them up too. Apple is a special case, it has special needs and I mean that in the most sincere way possible. And, don’t forget “Documents and Settings” there could well be lots of configuration files and documents in there that you should keep safe. Princeton University has a list of the common locations for Windows and Mac users.

Your email program may have its own special place for storing email files, particularly if you’re using Outlook, Thunderbird or another offline email client, so locate those and backup. If you’re running IMAP then your “backup” is the fact that your emails are all synchronised on the server, whether that’s Google Mail or some other webmail system.

Similarly, your browser favorites, bookmarks, weblinks could be in their own special folder, so don’t forget to back up those too, or better still synchronise them with your Google Account, XMarks, or a similar app and then you will not only have access to them from any computer, but you will effectively have an online backup. Mozilla and other browser systems have various backup tools that will grab your settings and favorites ready for backup.

Other applications that may cause problems are scanner programs and graphics packages which naughtily create sub-folders for scans and images, don’t backup the programs but do check in those folders for data files that you don’t want to lose and back them up. How to Haven has a list of image creation programs and other tips on backing up the whole drive.

Using an offline RSS reader? That could be another source of data loss. Export your subscriptions to an OPML or XML file and store that or better still synchronise the exported file with Google Reader or a similar online RSS reader so that you have  access from any computer as well as a web-based backup. Incidentally, Feedly is an excellent way to turn your Google Reader view into a magazine-type layout for a much more enjoyable RSS experience.

If you’re a gamer or musician you may have proprietary software that once again naughtily puts its data files in program sub-folders. Don’t forget those. Similarly, the configuration files for FTP clients and other utilities often contain data such as all your logins that you really wouldn’t want to lose, make sure you backup those too.

Files on your desktop? Back them up.

Skype or chat user storing conversations, contacts and downloads? Locate and back up.

Microsoft Office template files, autocorrect, and settings…

Music and video downloads stored by the downloading software? Check its sub-folders and back up.

If you buy and download programs from the web, make sure you backup those files and the licences as you may not have free second-chance access to the originals online.

There are limitless backup options, but don’t ignore those hidden data files. To be really safe you could use a second hard drive and simply backup the whole of the original before formatting or make an image file of your drive.

If I have overlooked any data files…please let me know in the comments…