Clean install Win7 on Dell Inspiron 1525: 0x80070570

I'm trying to do a clean installation of Windows 7 x86 on my Dell Inspiron 1525 laptop that I bought in July 2008. It's been running Windows Vista 32-bit without any trouble. Yesterday I purchased the Windows 7 Professional 32-bit upgrade from Digital River and downloaded the ISO. I've burned it onto two separate DVDs using different software and a different computer each time (the second time I used Alcohol 120% and made sure that it was on the slowest setting). Now I'm downloading the iso again.
Each time I try to install it (which has been many times, now, trying different configurations of partitions, etc) I get the error message "Windows cannot install required files. The file may be corrupt or missing. Make sure all files required for installation are available, and restart the installation. Error code: 0x80070570"

I've read through just about every thread I could find on this site and others and nothing seems to help. The only thing I haven't done is mess with the RAM, but I'd prefer not to do that as I don't have any experience opening up laptops (although I have built three desktops).

Anyone have any ideas/suggestions?

Thanks

Try Google. I found these two:

When you see the error "0x80070570 can't access files" on install click --> Cancel ---> you will be returned to the "Install Now" startup screen and - WITHOUT REBOOTING - just re-start the install.

you should type crc checksum into a search engine and download a program that allows you to check if the contents on the disk is the same as the iso file.

As I said, I already read and tried most of what I found on google and on this website. The only thing I haven't done that seems to apply is removing the RAM, which I'd prefer not to do because it's a laptop and it's still under warranty.

Does anyone have any other ideas or suggestions?

I just updated the BIOS and then tried installing it from within Vista while connected to the internet and got the same error message but this time error number 0x80070241

I just tried using my flash drive instead of a DVD and I'm pretty sure it worked.

Let us know.

Always burn your bootable DVD's with ImgBurn at 4x speed with Verify. Never fails.

You can also verify the disks you burned by loading them into ImgBurn. First load the ISO to confirm it says "bootable" in text at left, then add DVD and click Verify button.

Here is also the best tutorial on creating a bootable flash installer in case you need it: USB Windows 7 Installation Key Drive - Create