No.
1. Some computers don't even support hard drives.
2. Not all of those that do will have a connection for an external one.
3. Not all external connections are the same, so even if one is present, it can't be used with a drive that uses another connector (unless that connection is also present). For instance, you can't use an eSATA drive with a USB port, and you can't use FireWire with an eSATA port.
4. Not all operating systems support portable hard drives connected to a particular interface (though this is increasingly rare).
no, not all can fit in computers or laptops.
no
I think that all computers are compatible with some kind of presentation software, but it varies because different computers are no compatible with the same software.
This is done with a wireless access point and connecting all laptops and desktops together wirelessly. If the external harddrives have a networkport (RJ45), then you can connect them to a wired networkport on the wireless access point. If not, the external harddrives will need to be connected to the computers. You need to create shared folders on the external harddrives and the computers to hold the files and folders you want to share. You need configure the laptops and desktops to allow access. In windows XP you need to set up at least one userid and password on all computers that is granted access to the shared files and folders. In windows Vista and 7 you can use Public and then no userids and passwords are required. In XP, for computer A to see a shared folder on computer B, you need to use Map Network drive. You will find this in Windows Explorer (NOT Internet explorer, in the menu, select Tools and then Map Network Drive)
All computers are compatible with ATA hard drive, still.
all of them
It is compatible with a majority of PC's but not Mac.
Depends what you mean by "port", but that word is more often used for external connections that internal ones, so in that case ports are used for external hard drives but not internal ones.
Yes, virtually all major brand USB adapters are compatible with Macintosh computers.
MapleStory is compatible with some Vista computers, but not all.
Yes, the Xerox CopyCentre C20 is compatible with both PCs and Macs.
Yes, all vocaloid programs are compatible with English Computers.
There are laptop cooling fans that are compatible to all laptops, although these are external rather than internal. If you're having problems with your laptop overheating and want something that is compatible with a variety of computers it is best to purchase a laptop cooling tray. This is a fan that you place under your laptop that helps circulate the air and cool it down. You can get these from many stores including BestBuy and Target at an affordable price.