This Desktop is a HP xw4400 Workstation with W7 and Seagate Hard drives.
I used the 'Erase' program on Seatools Dos to wipe the Drives.
Now, with the CD Drive tray empty I get the message 'Non System Disk or Disk error Replace .................. .'
I had a bit of problem earlier so I wiped the Drives without saving.
I bought a new W7 program which I need to install.
Can someone advise me please.