You are quite puzzled about the question how to restore lost data without valid backup from Mac system. Although the Mac system is considered to be a safe destination where the files can be stored safely but in some cases the data can get lost like when you have deleted them. The loss of data can also occur when there is any error in the application or operating system. When the file system of the hard drive is corrupted then it can cause corruption of data, the drive may also get infected by virus. If you have the back up of the lost files then you can easily get them back. The Time machine is the inbuilt backup utility that can help you, it stores the copy of Mac drive files automatically and can be restored when required but sometimes the time machine fails. You don't have to worry as you can restore data without valid backup as the Mac data recovery software can help you. It scans the mac drive with an advance algorithm and all the deleted and corrupted files are shown in the preview for restoration. You can download the software and use it as its the best solution to restore lost data without valid backup.