Hi, Nettie! Nice to meet you. Well, as a semi-expert with computers, I can tell you that it making that "matrix-like" screaming noise is NOT good! That's your hard drive. I'm betting you're beginning to have motherboard problems. Before your entire pc stops operating, I would certainly have it checked (FAST!). I also would not attempt to do anyting REALLY important in the meantime.
I suggest you VERY quickly backup ALL, repeat, ALL your data (including saved ZT2 games and animals) because if the hard drive/motherboard goes, you're sunk. There IS no recovery from that (as far as data goes). System, yes. Data, no.
You said it "dumps physical memory" after about an hour? How much memory (RAM) do you have? How fast is your processor? Could be your computer isn't "up to" ZT2/ES
Now, you said you have two screens? First, may I ask why? The only reason to have a second screen is if you have a second computer. If you've gotten a newer, better screen, just put the old one in the backroom for emergencies. Having two monitors doesn't mean you have more space on your hard drive, see. :erm Use the better of the two screens. Only one can be plugged into your computer at a time anyway. If you're trying to plug two in, that could be the solution to the FIRST problem (but I strongly doubt it).
If you're getting the 'blue screen of death', that tells me you don't have Windows XP. If you've not upgraded, it's quite possible your original graphics card/s aren't up to the game, either. Those should be updated with the latest drivers and/or replaced with new ones (big $$).
That's all I can think of to tell you for starters. If none of that helps.... well, actually, I don't know what else to say. Sorry. :sad