Install a printer using IP address

Start > control panel > Printers and devices > right click Add Printer > Add a network, wireless or blue tooth printer > Printer was not listed
Check radio button "Add a printer using a TCP/IP address or hostname" > next
From pull down select "Device type" select TCP/IP Device
Enter Host name or IP address like 172.16.30.79
Ok

AutoCAD Workspace Switching

c:\program files\bentley\prostructures\v8i_s4\autocad 2012\localised\english\menus\prostructures.mnl

comment out this line

;;;(command "_setvar" "WSCURRENT" "3D Modeling")


CUI  menus, turn off menus and see if the switching is tied to a menu.