Is it possible to recover a lost iTunes library from a dead PC?

My original iTunes library was on a PC... this included songs that I had purchased, and CDs and vinyl tracks that I had imported into iTunes.

Just over two years ago, that PC died, though I still appear able to listen to my library, I wonder where is it..? Is it stored on the cloud (I don't think my library is though). I just don't quite get it. Furthermore, occasionally, iTunes would lose the odd track here and there, and I'm REALLY worried about that happening again.

And also, now, if I bought a CD and wanted to add that to my library, where do I do that.

Would appreciate any guidance.

[Re-Titled by Moderator]