Grub
Tidy
(see note below ref earlier versions of Ubuntu)…
To tidy the boot menu:
Check the version of the kernel you are currently running:
uname -r
Run Synaptic Package Manager.
Click Status in the bottom left hand corner.
Select Installed (local or obsolete).
Select the packages that start with
linux-i.e.linux-headers-*andlinux-image-*.Double check you haven’t selected the current kernel!
Right click on the selected packages and choose Mark for Complete Removal.
Click Apply.
Earlier Versions
Earlier version of Ubuntu don’t appear to have the option, Installed (local or obsolete).
To create the same effect, I installed startupmanager using Synaptic.
In the Advanced tab:
Tick the box to Limit the number of kernels in the boot menu.
Set the Number of kernels to keep to 2.