You most likely have one of these: 1. if you have a Mac, download the mac version. 2. You have an anti-virus program stopping it. 3. You're firewall might be blocking it because it doesn't have a valid publisher.
possibly bad video card drivers.
Yes you can, their worlds wont appear on your computer, all you have to do is download the minecraft application. there is no limit on how many users are on one account.
If its a computer then yes.
Minecraft.net
No.
Same way you get minecraft on any computer download it.
Minecraft.net download from there
if you download the wrong minecraft that is the 1.2.3.4.5.6.7 0.37
Yes, simply download it from the minecraft website.
you just have to download it on the computer you want that minecraft to be
you have to download it from your computer
no only gameboy advance
Yes you can, but you need to download minecraft for macs