If you have a 32-bit PC with more than 1 GB of RAM, be sure to install the “bigmem” version of the kernel to access the additional memory. (Other distributions such as openSUSE, Fedora, or Ubuntu, don’t require this.)

In Synaptic Package manager, search for “bigmem” or use dpkg --get-selections | grep bigmem to do the same via command-line.

After installing the “bigmem” version of the kernel, /boot/grub/menu.lst should be updated automatically, but if not, be sure to add that kernel to the list.

(On other distributions, older versions may have also separated the two — it may be called “hugemem” instead of “bigmem” for the kernel with large memory support.)