You can modify the files that you want to backup by selecting the common backup folders in your computer. These folders should contains most of your important files. By default we have a list of common backup folders for you to select, such as the Desktop and document folders. If you need to backup a particular folder that is not listed inside these common backup folders, you can click on the 'I would like to choose the files to backup' link, and a file tree of your computer folder structure will be shown. Click on the icon in front of the check box in the file tree to expand or collapse the tree. You can select the files by clicking on the check box in the file tree, all the files under the file tree will be selected.