Reinstalling only installs the software anew, but would never touch your personal files. The error is clear, something is wrong with your personal file (it's in your home directory, and the package manager doesn't touch files there): /home/bcm/.VirtualBox/VirtualBox.xml. You may check that folder (press Ctrl+H in your file browser to show hidden folders like this), there will be a VirtualBox.xml-prev file. You could rename the current VirtualBox.xml file to something else, and then rename the VirtualBox.xml-prev file to VirtualBox.xml. This file has a list of all your virtual machines, amongst other settings, so you might have to add one of your virtual machines again if it doesn't show up in the list (if VirtualBox will start again).
If that doesn't work, you could delete the file and VirtualBox will create a new (blank) file for you. You'll have to add all your virtual machines again though.
Before you try any of that, have you tried editing the file and fixing it? I don't have VirtualBox 4.2 but 4.1.18, but here are the first lines of my file. As the error says, it borks on the first line, first column. So it should hopefully be a bit obvious what is wrong. You can edit the file with the text editor.
- Code: Select all
** DO NOT EDIT THIS FILE.
** If you make changes to this file while any VirtualBox related application
** is running, your changes will be overwritten later, without taking effect.
** Use VBoxManage or the VirtualBox Manager GUI to make changes.
<VirtualBox xmlns="http://www.innotek.de/VirtualBox-settings" version="1.12-linux">