The .daa file extension stands for 'Direct Access Archive' and was created by PowerISO Computing for their CD/DVD image file-processing tool "PowerISO".
Unlike the majority of CD/DVD image formats, the .daa file format allows advanced features such as file compression, password protection, encryption and the ability to split files in to multiple volumes. Due to these advanced features, PowerISO is the only software package that can read the .daa format.
PowerISO is a fairly easy-to-use application that uses a simple drag-and-drop user interface and the (now standard) ability to copy/paste from the clipboard. It also supports shell integration (command line interface and scripting).
One of its main features is that it allows you to open, create (up to 64GB), edit and extract ISO files, allowing you to create backups of your valuable CD/DVD-Roms or to simply create CD/DVDs from files on your hard disk. Also, as it can recognise the majority of image file formats, you could convert your CD/DVD-Rom image collection over to the standard ISO format.
Another couple of PowerISO's useful features is the capability to create bootable ISO images (or make a non-bootable image bootable!) and create floppy disk image files.It also comes with an integrated virtual drive (similar to Daemon tools and Alcohol 120%) that can (obviously) mount .daa CD/DVD images, as well as other popular CD/DVD-Rom image file formats such as ISO, IMG, BIN, NRG, CDI etc.
Although you do not need a powerful PC to run PowerISO (Pentium 166Mhz, 64mb memory and 10mb drive space), it is only available for the Windows 98, ME, 2000/XP/2003 and Vista operating systems and unfortunately, the internal virtual drive component requires Windows 2000/XP/2003/Vista or above. As yet, there is no Apple Mac equivalent.
You can download a trial of PowerISO which, while unregistered will not create or edit images larger than 300MB but apart from these restrictions, all other features and functions are available.