Can't record in Win 10 or after update on older systems

I have bought a new Lenovo with Windows 10 installed. I have downloaded Audacity 2.1.3. but cannot get it to record from my three pole lead from my hi fi system as I used to before on Windows 7. I have bought a 3 pole to 4 pole adapter, bit it hasn’t made any difference. Can anyone help me?
John Eldridge

Does your Lenovo have a built-in mic?
If so, are you able to record with that?
Which model of Lenovo?

I have bought a 3 pole to 4 pole adapter, bit it hasn’t made any difference. Can anyone help me?

If your new computer has a single-combo microphone/headphone jack, that’s correct… if you were trying to record with an external “computer mic”.

from my hi fi system as I used to before on Windows 7. I

Was the old computer a desktop/tower with the 3 regular soundcard connections (mic-in, line-in, and line/headphone-out)?

The mic input should “work”, but it’s the wrong connection for a line-level signal… The mic input has too much gain, it’s often noisy, and usually mono… The 4-pole combo connectors are always mono (stereo headset, mono-mic, and ground).

If your laptop doesn’t have line inputs, you need a USB audio interface with line inputs. The [u]Behringer UCA202[/u] is a popular, inexpensive, option. Don’t get a regular “USB soundcard” because they are like laptops with only mic-in and headphone-out.

Have similar situation with a Dell E6520 with combo jack.
Solved this by buying a cheap docking station with regular line-in jack for vinyl disk digitization.
Connected my headset mic via a Sennheiser 2-in-1 adaptor-cablet.