How do I upgrade the kernel in Ubuntu Server 10.04?

I'm running Ubuntu Server 10.04 LTS. When I login I see the message:

39 packages can be updated.
18 updates are security updates.

The usual formula of

sudo apt-get update
sudo apt-get upgrade

gives me a message I've not seen on this box:

The following packages have been kept back:
  linux-headers-server linux-image-server linux-server

If I give the go ahead to the apt-get upgrade the rest of the packages are upgraded as I expect.

How do I update the kernel files?

EDIT: I missed this earlier question and answer that basically solved my problem:

Can someone clarify Ubuntu (Debian) dist-upgrade for me?

Solution 1:

Usually, in this case you would want to use apt-get dist-upgrade

If you do not wish to run dist-upgrade by fear of breaking something by an accident removal, you can also tell apt-get to upgrade only the packages that were kept back, like this:

In your case:

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

Just specify the packages from the list that apt-get gave you (i.e. "The following packages have been kept back").