E1505 with T5600 Core 2 Duo CPU. 64bit Win7 won't install.

I got an E1505 for cheap, missing the battery. So for a few $ I got a T5600 CPU, a new battery and upped the RAM to 4 gig. Yes, I know it can't use it all. I also moved my 500 gig drive from my older laptop and setup the Dell Media Direct partition for DMD 3.5.

Before I swapped the hard drive I used the XP that was on it to run the latest BIOS update.

To install Windows 7 I made a bootable USB stick but some time after the expanding phase it gave a message about not being able to install some driver and restart setup. So I rebooted and get the message about not being able to install after the Starting Services screen.

I know others have installed 64bit Win7 on this model with a 64bit CPU upgrade. What is the trick to it? Perhaps putting the 1.5 gig RAM back in that it had? Or doing something to integrate the drivers into the install so it can't claim it can't find drivers.

I downloaded 64bit Vista drivers from Dell, and from chip/device manufacturers where Dell didn't have the drivers. Then I decided I may as well try Win7 so it'll be good for a long time.