Recording Through The Computer

I am a music teacher and over the summer, the school installed new computers in our rooms. I was running an older version of Audacity but with the new compter I am running 2.0.3 with Windows 7.
With the old computer I would find a sample of an instrument online and just hit record on Audacity and it would record it while it played. I could save the sample and use it for an audio test. With the new setup, when I hit the record button I get an error message about checking the input device.
What can I do to fix this issue?

Simple self-recording isn’t possible on all computers, but if it is on yours, the setup should be no more complicated than it was on the old machine.

See if any of this is helpful.

Self-recording and recording a microphone tend to fight each other, so you do need to be careful on multi-use machines.