Test the HD and RAM to see if you have failing/failed hardware. In addition to memtest86 and maker's diag/repair CD scans linked in my prior post, run Disk Check
from DVD Command Line by pressing Shift + F10 at first screen.
What happens when you try to boot the Windows 7 DVD? Can you get to the first screen to press Shift + F10 to open a Command Line to wipe the HD: SSD / HDD : Optimize for Windows Reinstallation
Try also to Select 1 for screen resolution before PW CD times out. PW should autostart to avoid needing to boot it, then once it wipes the HD the Installation DVD should autostart.
What happens if you press Alt + F10 to try to boot Acer Factory Recovery?