I remember that this has been a problem since vista came out. It works ok on xp and below. the only way that was ever discovered to "fix" it was to rename the ALBRIEF.DLL and EMBRIEF.DLL files. This will still go through the briefing, but skip all the spoken dialog, so it only takes like 2 seconds.
Works. But there is already an EMBRIEF.DLL in the game folder. The file is then automatically renamed in EMBRIEF (2).DLL. I think you can rename it as you like. As long the game isn't able to find the ALBRIEF.DLL, the tutorial will be skipped. ;)
I figured out that this only works for the Rebel faction. If you play the Empire you have to rename the EMBRIEF.DLL too.
I Renamed the DLLs in ALBRIEFX.DLL and EMBRIEFX.DLL. Deleting those files will probably also help but now I'm able to restore them if I like.