How I got my 4GB groove back

Intel Core 2 Duo
ASUS P5B-E motherboard (Intel 965p chipset)
4x1GB DIMMs
Some random nVIDIA graphics card
Ubuntu 7.04 "Feisty Fawn" i386 (32-bit)

1. Install the Ubuntu "server" kernel, which supports PAE for up to 36-bit physical memory addressing:

   sudo apt-get install linux-image-server linux-headers-server

2. The Linux kernel mistakes the 965p chipset for a 965g chipset with built-in graphics; when the BIOS has memory remapping enabled, the kernel dies while probing for Intel AGP support. Blacklist the Intel AGP module:

   sudo sh -c "echo blacklist intel_agp >> /etc/modprobe.d/blacklist"

3. Download the (non-free) NVidia driver installer
4. Reboot
5. Bring up the BIOS setup screen: press Delete when the splash screen appears upon booting
6. Enable "Advanced > Chipset > North Bridge Configuration > Memory Remap Feature", press F10 to save changes and reboot
7. In the GRUB boot menu, choose "Ubuntu, kernel 2.6.20-16-server"
8. Don't bother looking at the logs when the X server fails
9. Log into the console, install/update the graphics driver and compile a new nVIDIA kernel module:

   sudo sh NVIDIA-Linux-x86-100.14.11-pkg1.run -a

10. Restart the GNOME display manager to log in to X:

    sudo /etc/init.d/gdm restart

11. Profit?