First, you need a "recording" program so you can record the Line In audio to the Pc's hard drive. The free (and very popular) Audacity program will do that. There is a Windows sound recorder but I don't recommend that. Audacity even has some capability to remove noise, pops, clicks, etc from the old vinyl.
When playing a vinyl (e.g. 33 1/3 LP) you can't connect the turntable direct, you need a preamp that has an RIAA equalizer option (e.g. phono input on the preamp). If you have a preamp that does not have the RIAA, the recordings will sound bad.
As far as the input settings, go to the Control Panel/Hardware and Sound and finally the Sound Panel. Click the Recording Tab and it should list your devices such as Line In, Mic, and if you are lucky "System Mixer". If you have the System Mixer it should cover any input and if you are hearing the Line In input on the PC's speakers then you can use the System Mixer as the default recording device (set it as the default recording device). If you do not have the System Mixer, you should set the Line In as the default recording device.
Whichever device you will be using (System Mixer or Line In) needs to be set as the input device in Audacity. You can then record your vinyl and save it as wav files on the hard drive. Save them as wav, not MP3 as a wav file is full fidelity, MP3 files are "something" less than full fidelity.
Bascially, this is the same as recording in XP, just may be different terminology or different display of the sound in the Control Panel. Audacity: Free Audio Editor and Recorder