incomplete update(?) trashed my system

[Charles Blair <c-blair@illinois.edu>]

   I have been running a dual-boot linux / windows system on a
Toshiba laptop for several years.  According to
/etc/apt/sources.list,  the system is 
wheezy, installed with binary 20140209-16:42.

   When I turn the machine on, I get the usual GRUB
multi-boot display.  The windows boot seems to be
working correctly.  When I boot linux, I get what
seems to be a screen of normal messages, then the
screen goes gray with a wristwatch icon, and it
just stays that way.

   If I type control-alt-F1, I get put into a character-
based terminal, and am able to log in, run emacs for
simple file editing, and download files.  However,
if I type startx, I get the debian spiral logo,
followed by a screen saying something has gone wrong
and my system has been shut down for my  own protection.

   A guess as to the cause of problems:

In the last few days, I have received messages about
updating my system.  When I have authorized the update,
something goes wrong and the process halts.  In at
least one case, I got a message about insufficient
disk space on my /root partition.  I tried to fix
this problem by clearing the cache on iceweasel,
and the update seemed to give me different failure
messages subsequently.

   Output from df:

Filesystem         1K-blocks    Used Available Use% Mounted on
rootfs               330215  239888     73278  77% /
udev                  10240       0     10240   0% /dev
tmpfs                400736     684    400052   1% /run
/dev/disk/by-uuid    330215  239888     73278  77% /
/0923b264-3863-4302-b3a3-23fd36f4ab8e
tmpfs                  5120       0      5120   0% /run/lock
tmpfs               2457460       0   2457460   0% /run/shm
/dev/sda10        176581224 1266084 166345312   1% /home
/dev/sda9            376807   10265    347086   3% /tmp
/dev/sda6           8649992 5981124   2229472  73% /usr
/dev/sda7           2882592 2430340    305820  89% /var

   
   Output from du --max-depth 1 /root:

21	/root/.pki
891	/root/.gstreamer-0.10
16799	/root/.mozilla
4	/root/.pulse
1	/root/Pictures
26200	/root/.cache
11	/root/.gconf
1	/root/Music
4	/root/.dbus
1504	/root/.config
52	/root/.gnupg
1	/root/Downloads
3	/root/.mission-control
278	/root/.local
428	/root/.gimp-2.8
1	/root/Templates
1	/root/Videos
28	/root/.gnash
48	/root/.scid
1	/root/Desktop
24641	/root/.claws-mail
1	/root/Public
3	/root/.gnome2
11	/root/.aptitude
8	/root/.thumbnails
2	/root/.emacs.d
1	/root/.gvfs
1	/root/Documents
1	/root/.gnome2_private
55	/root/.texmf-var
71244	/root