How do you add drivers to a Windows 7 installation?

I'm trying to format my HP Envy 15 1104TX but as far as I know there are only 2 USB 3 ports built into the computer itself. The Windows 7 (non-SP1) installer doesn't have necessary drivers to read from these two ports, causing a loop around the "missing CD/DVD drivers" section. I've tried the port swap fix, but it doesn't work since they're both USB3.

My real question is how do I add drivers to my Windows 7 installation ISO? I've seen a few guides but they're either badly worded or too difficult to understand. If someone from here could give the quick rundown, it would be greatly appreciated.

Note: Will I be able to just slipstream the SP1 update and the .inf drivers onto the ISO using RT 7Lite?

Since on some systems, as perhaps yours, the USB 3.0 ports are not operational until windows 7 is installed. There may be a setting in the Bios to set USB 3.0 to enable legacy USB, which might help.

But I was able to install USB 3.0 drivers during a System recovery operation using a flash drive. But if you cannot read a flash drive during the install process, I suppose this will not work. It is a little hard to conceive of a system that has no useable USB ports during an install....

The drivers I used for my Intel USB 3.0 ports were downloaded from the manufacturers site, or possibly on a Driver disk you have. For intel, I needed the setup file and associated files for it and those two .inf files were iusb3hub.inf and iusb3xhc.inf. Yours, will of course, will be dictated by the controller manufacturer.

You can download a Windows 7 SP1 Install DVD .iso file from here and burn as an image.

Official Windows 7 SP1 ISO from Digital River « My Digital Life

Let us know how it is going.

Edit: I found this on the HP site

If your HP ENVY 15 comes equipped with USB 3.0, only the eSATA/USB 2.0 port may be used for USB devices while in HP QuickWeb mode

So there is a USB 2.0 port, you just need to try until you find it.

Make sure you have a bootable stick as the error most often if a bad installer. The ISO and tool to burn it are in Step 1 and 2 of this tutorial to get a perfect Clean Reinstall - Factory OEM Windows 7 - steps are the same for retail.