FYI, DriveHQ Online Backup is designed for best protection of your files. If you have delete a file from your source folder, or if you modify a file in the source folder, the deleted file or the modified file is still kept on DriveHQ.com. This protects you from accidentally delete/modify files. If you are sure that you don't want to keep the deleted files or the old versions, you can delete them using DriveHQ Online Backup. Go to Manage Tasks, select the task and edit it. You can click on the button "Delete un-used files on Server" to delete them; you can also set less versions to keep.
If you don't want this level of protection, you can use DriveHQ FileManager's folder synchronization feature. Be careful that folder synchronization doesn't protect you from accidental deletion.