Environment:
Fresh Windows 7 SP1 x86 Installation
Fresh CCSv5.1.0.04001 installation (MCU Variant)
When trying to launch Stellaris code I get the error message (in german)
Unable to load "..\..\..\emulation\tpi\tpiarm_x.dll": Das angegebene Modul wurde nicht gefunden. (Translations: The specified Module could not be found")

I could fix the issue by adding the folder to that windows path as recommended here:
http://e2e.ti.com/support/development_tools/code_composer_studio/f/81/p/89055/310844.aspx
Still I believe this is a bug that should be fixed properly. If you need any more infos let me know, we have multiple affected systems.