From Norganna's AddOns
Backing up your SavedVariables
A step-by-step guide to backing up your SavedVariables files
Whenever you upgrade your AddOns, if you have valuable data which you wish to save, it's very important to make an archived copy of the SavedVariables file for that addon. You may also choose to use a Batch Script to make backups easier and more automated.
In order to backup your SavedVariables files for Auctioneer, you must first locate them. They are located in your World of Warcraft\WTF\Account\ACCOUNTNAME\SavedVariables folder. Here is an example of what you are looking for.
Once you have located your folder, you then need to select the files you wish to backup.
In general, we recommend simply backing up the entire SavedVariables folder. If you do not want to back up the entire contents, important files to consider are any file beginning with Auc and other related saved variables, such as Beancounter, Enchantrix, Informant, and Stubby.
Then go to the edit menu and select the Copy to Folder option.
A dialog box will pop up asking you to pick the folder to copy the backup files to. Browse until you find your account folder World of Warcraft\WTF\Account\ACCOUNTNAME, and click the "Make New Folder" button at the bottom of the dialog box.
Name the new folder backups and create another new folder underneath it.
Name the subfolder after today's date so that you will know when the backup was made. In the future when you make backups they will also be dated, so you won't confuse them with the ones you make today. When you've typed today's date, simply click the Copy button at the bottom of the dialog to complete the process.
And that's it, your important saved files have been backed up. Should you need to restore them in the future, simply copy them back to the original folder using the reverse of the above procedure.