How to downgrade the Kernel on 11.10

How can I do...

You could download the kernel binaries from the old or new Ubuntu releases /1/.

Ubuntu Packages Search: http://packages.ubuntu.com

Picking natty-updates kernel linux-image-2.6.38-10-generic : http://packages.ubuntu.com/natty-updates/linux-image

Downloading it and installing with the command:

sudo dpkg -i linux-image-2.6.38-10-generic_2.6.38-10.46_i386.deb

Package management is telling:

Selecting previously deselected package linux-image-2.6.38-10-generic.
(Reading database ... 127436 files and directories currently installed.)
Unpacking linux-image-2.6.38-10-generic (from linux-image-2.6.38-10-generic_2.6.38-10.46_i386.deb) ...
Done.
Setting up linux-image-2.6.38-10-generic (2.6.38-10.46) ...
Running depmod.
update-initramfs: deferring update (hook will be called later)
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 2.6.38-10-generic /boot/vmlinuz-2.6.38-10-generic
update-initramfs: Generating /boot/initrd.img-2.6.38-10-generic
run-parts: executing /etc/kernel/postinst.d/pm-utils 2.6.38-10-generic /boot/vmlinuz-2.6.38-10-generic
run-parts: executing /etc/kernel/postinst.d/update-notifier 2.6.38-10-generic /boot/vmlinuz-2.6.38-10-generic
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 2.6.38-10-generic /boot/vmlinuz-2.6.38-10-generic
Generating grub.cfg ...
Found background image: /lib/plymouth/themes/my-plymouth/my-wallpaper.png
Found linux image: /boot/vmlinuz-3.0.0-12-generic
Found initrd image: /boot/initrd.img-3.0.0-12-generic
Found linux image: /boot/vmlinuz-2.6.38-10-generic
Found initrd image: /boot/initrd.img-2.6.38-10-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Microsoft Windows XP Professional on /dev/sda1
Found Ubuntu 10.10 (10.10) on /dev/sdd1
done

Rebooting

Picking from the grub > Previous Linux versions > Kernel 2.6.38-10

...and the (K)Ubuntu is telling that i'm running with the 2.6.38-10-generic /2/.

...won't it cause any problems?

Well ;) you could tell us...

Links

1. http://www.kubuntuforums.net/showthread.php?51992-FAQ-Kernel
2. http://www.kubuntuforums.net/showthread.php?53976-FAQ-Version-info-Regenerated