If the program crashes on start up. Uninstall PCB123, then go to
xp C:\Documents and Settings\All Users\Application Data\PCB123
copy your lib, designs and backup files folders to an safe location then delete the PCB123 folder. Download the PCB123 installer from the Sunstone website and save to your desktop. Extract the installer to your desktop and run the msi. Please contact customer support if you have any questions.