Ask the Gentoo hard disk installation problems

I recently studied Gentoo hard disk installation, but after Grub4dos guided, in Activmdev place "the root block device are unspecified or not detected!
Please specify a device to Boot,or "shell" for a shell ....
Boot ():: "The problem, the specific is that I put gentoo down from the Internet, and then use the virtual optical drive to extract the files inside the C-disk Gentoo directory, in the use of PQ partition I want to install in the same hard drive, but the same hard drive can only have 4 primary partitions, I only keep a C-disk primary partition, then all do Linux partition, a/boot partition as the primary partition, one/partition is the main, and then divided into a/swap exchange partition, do not know if there is a problem with this partition. Please enlighten us. Linux partitions are generally/boot primary partitions,/USR primary partitions, and/or the master partition, and then the extended partition has/home logical partition and/TMP logical partition and/SWAP Exchange partition, but on a hard disk to exactly how to partition the good. In the case of coexistence with Windows.

And I wrote the Menu.lst in the grub4dos.

Title Gentoo Linux on (hd0,0)/gentoo

Root (hd0,0)

Kernel/gentoo/isolinux/gentoo Root=/dev/ram0 INIT=/LINUXRC Acpi=ht
LOOPTYPE=SQUASHFS LOOP=/LIVECD.SQUASHFS Udev Nodevfs
Cdroot=/dev/hda vga=791 Dokeymap
splash=silent,theme:livecd-2004.3
INITRD =/gentoo/isolinux/gentoo.igz

One of the main partitions I wrote hdd0, no, written hdd1 also not, and then read the analysis of others written hda0, error, I changed to HDA, but still appear "the root block device are unspecified or not detected!
Please specify a device to Boot,or "shell" for a shell ....
Boot ():: "