Entering into a computer through internet

Yes you can , the FTP application helps in achieving it. You can also achieve using some softwares. I think Ipmsgr also can help you.

Depend if you can access his computer or not yea .

yes, you can. like if your friend's PC has a public ip address, and your friend allows you to access his PC, you can use a remote desktop connection.

People have been entering and sometimes control other people's computers for some time. Peer programs is a mild form where we can copy files such as movies and songs. This method can be considered as harmless since we do not allow other users to completely access our hard disks. The second method is intruding without permission, getting full access and enabling the intruder to do whatever they like to our hard disk. As I understand it this method is illegal.

surely,you can.you can use your u disk to copy the games files and make it into your computer .

its illegal if you get caught. try a program called vnc.