I have 2 drives with raid 0 (that my os is on) connected to my VIA serial ATA controller. I want to connect a 3rd drive as additional storage. I connected it to my onboard promise RAID console. I booted up the computer and installed the seagate disk wizard to add a secondary drive. It added the secondary drive just fine. However, the next time I rebooted I got a message: ERROR no OS. I shut down the computer and unplugged the drive and windows loaded fine. The one thing I did do was copy a bunch of files to the drive, including hidden files and OS hidden files(I was trying to see if I could make my own ghost image, but it didn't work because it couldn't copy several files). In the wizard I set up the drive as additional storage, not a boot drive, so I don't understand how any boot files or operating system files are causing this error. I am not very familiar with DOS, but is there a way to boot from a start up disk and format the dirive? I don't think that is the problem but at least it would be something to try. Thanks in advance for your help.