RAID help, I think

The problem is that this is a "catch all" error message for when Windows simply cannot read the disk, meaning that this error, 99% of the time, means your DVD is bad. 

I would see about ordering a new disk from Dell, OR ... you can try burning a new disk:

On occasion, when older DVD drives won't read a DVD properly, a newer drive will, then you can create a new disk. Put the Windows DVD into the newest/best DVD drive you can find, copy the disk, then burn back to a new DVD.  I would recommend downloading and installing ISORecorder on the computer you do this with, then to copy the disk, simply right-click on the DVD drive in My Computer and choose Create image from CD/DVD, then you can right-click that ISO file and Copy image to CD/DVD.

That's the one. Tried downloading drivers and outing them on external hd but still not working

Is this your problem:

Trying to reinstall, you are getting a required CD/DVD driver is missing (or similar) message?

It is a new dvd, but the dvd drive is very old at this point, and sometimes didn't read dvds on the first try. I have an external dvd/rw that reads the vista disc ok, but i need a way to have the pc recognize the drive. I have the drivers, but don't know where to put them. Even if I can, will this work?

Your system is new enough it "should" be able to boot from a USB device.  You won't need drivers for it though ... just hit F12 after the system turns on and select USB device. Another even better option (assuming your system will boot to USB and you do have a good DVD) is to install from a USB key (flash drive) - I rarely use DVD's anymore: http://www.intowindows.com/how-to-install-windows-7vista-from-usb-drive-detailed-100-working-guide/

That worked!!!!! Thank you so so much for your help. I would advise anyone who encounters the same problem to jump straight to this solution.

Thanks again!

No problem ;)