If you have a Windows XP instance installed from nLite disk or other type of automated or scripted install, you might experience this problem. You are trying to add a new language and a new keyboard layout in Control Panel –> Regional Settings, but your favorite keyboard layout is missing from the drop-down list.
What to do? You need to find a normal XP workstation and grad two things from it.
First, you need to export registry branch [HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlKeyboard Layouts]
Second, you need to copy a DLL that holds your keyboard layout (for example KBDRU1.DLL) from SYSTEM32 directory.