Fonts essential to Windows?

Having just received the Extensis Suitcase 9 for Windows, I am puzzled to decifer what exact fonts are essential to Windows (and thereby, the ones I should leave in the Windows/Fonts folder, with the remainder of my collection contained in this Suitcase). How do I make this determination? Is there a list somewhere?

How many fonts are too many for this Windows/Fonts folder? I’m at 334 right now.

Thanks all.