SQL Developer

Hello all, I have quite a peculiar problem regarding the what I've come to find fairly common error, "Network Adapter could not establish the connection."

Now, before you close the tab/page/browser, hear me out -- I've looked through at least two dozen threads with this topic, but none share the same situation I have, and none have supplied any help whatsoever.

I'm a college student in a databasing class of 12 other students, where the instructor created a sql developer setup batch file and package, so that all copies of SQL Developer would be absolutely identical. As well, all machines within this classroom are absolutely identical as well, being imaged school harddrives in identical hardware computers. Within the classroom environment, we use database connections on localhost for the purpose of training. The instructor wrote the batch file to set the listener and start the service. Somehow, I receive the above error while no other person within the room has a problem.

I have verified that the listener is set to listen on localhost and port 1521, and that I am connecting to localhost and port 1521.
- I have attempted changing the listening port.
- I have attempted changing the listening IP to 127.0.01, this machine's network IP, this machine's internet IP, this machine's name, and this machine's qualified domain name.

I have verified that the listener service is operating.
- I have attempted stopping and starting the service.
- I have attempted changing the service to manual startup, rebooting the computer, and restarting manually.

I have verified that the network adapter is operational.
- Used Ipconfig /release and /renew
- Can ping self, as well as all other computers in room.
- Can ping the default gateway
- Can tracert the default gateway
- Have DNS connectivity

I also attempted a fresh copy downloaded from oracle on my personal laptop, and manually used the same settings as the instructor prescribed. I received the same error, where I attempted all items in the above list to no avail. I then moved to another machine in the room, which also did nothing, and finally I moved to a machine that another student had already used, which worked fine.

Working at my own workstation now, I finally attempted simply running as administrator, which attained the same error, and I rolled back my version of Java, which still received the same error.

At this point, I have exhausted everything I know to do, and am quickly becoming frustrated. Neither my workstation nor another unused computer within the room work. My personal laptop not connecting doesn't bother me. If anyone at all has any advice whatsoever, I'm all ears. I'd even make sure it's plugged in at this point.