Setting The Mixer Controls
Before you can record to a PC you need to set the mixer controls for Line-In recording. Double click on the volume button in the system tray (either a small yellow or grey speaker depending on your version of windows). The playback controls will open. Make sure Line-In is not set to mute.
We now need to set the recording control so select Options>Properties . The default view is for playback but we want Recording.
We want to see both the Line-In and Microphone on the recording volume controls so check both and press ok. I choose Microphone for reasons that will become clear!
You now need to select Line-In and make sure that Microphone is not selected as you may get corrupt recordings from feedback noise when this is selected. Note that this is the place where you need to adjust the volume for your recordings if they are being recorded too low or high. Adjust the slider button accordingly.
Notes
Most recording software has the option of going to the mixer controls direct from the program so you can adjust the settings from there.
Some soundcards have their own mixer controls so you need to set the above from those. The soundcard I use has this and they are completely independent from the windows mixer so just double check if you are using the windows mixer without success.
If required, make sure that your tape monitor is selected or set the record selector on your amplifier if no signal is coming through.