The control panel applet usually crashes when it is not able to correctly access/read the printer drivers.
The easiest solution but make sure you are logged on as an administrator is:
Delete both printers from Printers and Faxes. Remove one of the printer USB cables, as it best to get one printer working again first.
Reboot PC, windows should now detect USB device/Printer and either:
prompt for install cd or ask if you wish to use existing drivers. If possible use install cd.
Once install is complete, reboot pc.
View printer in Printers and Faxes, share printer again and check defaults etc. Once complete click apply then close printer dialog box. Reopen and then select Test page.
Finally, plug-in second usb printer cable and repeat install as above.