old computer as an NAS device

I was at a site listing how to build my own NAS server from an old computer. I have followed the process using one of my old computers. It has no operating system, three hard drives and a CD Rom. On my regular compouter, one I am using for this message, which is Windows 7 Pro. I downloaded the ISO recorder, and the Free NAS SOFTWARE. I installed the ISO recorder software, then using that software I burned the .ISO file to a CD. Then I placed the CD into the old computer as directed booted the old computer. Nothing happened except I got a screen with a note " boot loader failed, instert system disk. As I understand the process, the iso program was to start the process of setting up the old computer as an NAS server, after following the instructions. I did comfirm the old computer first boot from CDROM. What am I missing? One set of instructions on one site said boot from the CD on your computer and install the NAS server on a flash drive, was reluctant to do that with my primary computer. Any help would be appreciated.

Sounds like there may be something wrong with the CD you burned. I highly recommend using the usb method unless you have multiple hard drives. If you look at the warning here on figure 2.2
http://doc.freenas.org/index.php/Installing_from_CDROM
you'll notice if you install it to the hard drive you cannot use that hard drive for storage.

I have little knowledge about hardware but I like this post and i want to discuss one query with you.
Why you are not using portable hard drive?

thanks for the info guys. it'll really help me.

Make sure that the NAS server BIOS is set so server will boot from CD-ROM drive. It may be booting from the hard drive without OS

Try FreeNAS : it is very compact free, boot from USB too !!!

Thanks for sharing useful information.