Choose the startup disk in System Preferences. It would be:
System Preferences - Startup Disk - make sure the internal HD is highlighted then click restart to test.
Also it would be very helpful if you:
a) completed your Profile so at least we know the version of OS X is installed
b) answered den.thed's question about what update you're referring to.
If you don't know how to complete your profile click Your Stuff in the upper right of this page then select Profile and complete as needed.