I wouldn't uncheck the antivirus if you find it there. Nor the hardware related stuff like a touchpad driver, audio settings or Intel programs for the display. But that's up to you.
Windows 7 will certainly start if you uncheck everything, and if you find you unchecked too much, just check again.
when using xp it was safe to uncheck everything listed in msconfig start.
Is it also safe to do this in win 7?