In some instances, AutoCAD and it's verticals will stall at the Visual C++ 2008 redistributables. This typically happens on Windows 7.
The solution is to set the registry size to unlimited and rebooting:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control
Key: RegistrySizeLimit
Type: REG_DWORD
Value: 0xffffff (4294967295)
David Lau