Red Alert 1 & 3 comparisons (pretty BIG, not in the game)

I was sorting out hard drive few minutes ago, I found something interesting, not in the game (TRUST ME, FOR THOSE WHO SAID I'M A MANIAC FOR RA!!! EVENT THOUGH I AM)...

I saw this, RA 3 beta, just a beta okay... And it eat my space up for:
917MB... And is just a BETA, not a full game, reasonable... But when you see Red Alert 1, it use up:
37? A Full game just 37 MB, and full of music and sounds and effects... While the beta is just multiplayer only, imagine the full game....

5GB???
I Don't Know...