Download cd/dvd driver for windows 7

When I go to install Windows 7 Ultimate 64-bit, I get to the screen to select language, time, and currency, click next and this alert pops up:

Required CD/DVD Drive Device Driver is Missing.

It asks me to insert the disk or browse to find the file. I have no clue what driver it's talking about though. I copied all the drivers from HP onto a USB and none of them were recognized as the proper driver.

I've heard some people say it has to do with the SATA controller or changing BIOS settings to IDE ATA/ATAPI... Not highly hardware inclined here. I went into the BIOS and couldn't find that setting anywhere or any "advanced" menu as some people had mentioned it might be in.

I also found a question on server fault that said to check the .iso hash, but I did that and it was fine. So, I know the file isn't corrupt.

My laptop doesn't have a disk drive but I've tried two methods just in case that was the reason:

1. I've burnt Windows 7 Ultimate cd and have an external CD/DVD drive (Memorex)
2. I have a usb flash drive that is formatted to boot Windows 7 using the Windows 7 USB/DVD Download Tool.

Both methods have produced the same outcome. Unfortunately our company doesn't yet have any IT support, we're just starting up. Any help would be greatly appreciated.