NOCD.SI
NOCD.SI is an SI file. It's the only SI file that gets transferred to LEGO Island's install directory, the rest remain on disc. Its contents are a Smacker video stream.
Details
Officially, NOCD.SI is played whenever the LEGO Island disc is not inserted. Specifically, it plays when it cannot find Lego\Scripts\Isle\ISLE.SI in either the "diskpath"^{{#if:| }} or cdpath^{{#if:| }} (having without the other SI files will cause LEGO Island to softlock on startup).
The three second video features the Infomaniac who charmingly tells you that there is no CD inserted.
NOCD.SI was actually meant to play if the CD was ejected during gameplay. In the game exists an unedited version of the Infomaniac's dialog which says "Whoops! You have to put the CD back in your computer.". The final version of this line crudely edits out the word "back". It seems this line was finalized to only be played if the game starts up without a CD before the game was localized, as the dub versions do not have this cut.
Language Differences
In the English release of LEGO Island, the Infomaniac says "Whoops! You have to put the CD in your computer.".
File:NOCDEnglish.wav
In the German release of LEGO Island ("Abenteuer auf der LEGO Insel"), the Infomaniac says "Hoppla! Leg' die CD wieder in deinen Computer ein.".
File:NOCDGerman.wav