Ata or ahci on windows 7?

Hi,
i have a problem while installing a clean w7 on a dell xps 1645.
Everytime, during the "file expantion" of the installation, i've got an error at 99% saying something about missing file (i use the official dvd from dell).
So i call dell, and they tell me to try different things:
1) flash a new dvd firmware
2) change in to the bios, from ahci to ata for the SATA settings.

I didn't try the first one, because the man who told me the second option, assure that during the file expantion nothing is readed form dvd, so the only possible reason is the aci/atha settings.

He tell me to let ata in bios, also after the installetion of the new os.

I don't know why, but im not sure about this second option...
Does someone had the same problem?
Is that correct, to let ATA settings instead of AHCI?
many thanks

 

The AHCI stuff can prevent Windows XP from installing properly, but it should not hinder Windows 7. You can try switching the ATA/AHCI settings; it's not going to do anything bad to the system, but I doubt it's the issue.

I'd guess that your DVD is damaged/scratched (even if you're not reading directly from the media; the installer might be trying to extract corrupted data copied earlier) or maybe even that your hard drive has a bad sector or something.