Can You Run Raspberry Pi Off Your PC's USB Port?

Depends. Safe answer : "No"

I found out the hard way when Windows said "Power surge on USB Port", then something about port on USB hub being disabled.

Happened when I ran "sudp apt-get upgrade" and the process got to upgrading "wireshark" - aha!

When I rebooted, and tried the upgrade again, Pi said "dpkg was interrupted, you must manually do 'sudo dpkg --configure -a' to fix the problem..

Seems to be turning into a nigthmare :(

pi@raspberrypi ~ $ sudo apt-get install ssmtp
Reading package lists... Done
Building dependency tree
Reading state information... Done
ssmtp is already the newest version.
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 wireshark : Depends: wireshark-common (= 1.8.2-5wheezy13) but 1.8.2-5wheezy11 is to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).
pi@raspberrypi ~ $ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
E: Unmet dependencies. Try using -f.

Might be able to recover :

pi@raspberrypi ~ $ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
E: Unmet dependencies. Try using -f.
pi@raspberrypi ~ $ sudo apt-get upgrade -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
The following packages have been kept back:
  gir1.2-freedesktop gir1.2-glib-2.0 glib-networking glib-networking-common
  glib-networking-services gnome-accessibility-themes gnome-themes-standard
  gnome-themes-standard-data libatk1.0-0 libatk1.0-data libgail-3-0 libgcc1
  libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgfortran3 libgirepository-1.0-1
  libglib2.0-0 libglib2.0-bin libglib2.0-dev libgomp1 libgtk-3-0 libgtk-3-bin
  libgtk-3-common libjavascriptcoregtk-3.0-0 libpango1.0-0 librsvg2-2 librsvg2-common
  libsoup2.4-1 libstdc++6 libwebkitgtk-3.0-0 php5 php5-cgi php5-common zenity
  zenity-common
The following packages will be upgraded:
  wireshark wireshark-common wpagui wpasupplicant xdg-utils
5 upgraded, 0 newly installed, 0 to remove and 35 not upgraded.
1 not fully installed or removed.
Need to get 0 B/2,086 kB of archives.
After this operation, 1,024 B of additional disk space will be used.
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