So - now that we've got that out of the way (we have, haven't we?)...
you should consider upgrading to Windows 10 before you suffer a catastrophic failure. Yes, I know all the reasons why you haven't moved up to Windows 10 (well, I don't, but I don't need to know).
In case you think you're being hard done by, or that I'm just digging at you, I will mention now that I avoided Windows 10 for as long as I could. In the end, Microsoft placed a pop-up on my old machine to inform me that it would no longer run Windows 10, even though they previously told me it would, so just as well I hadn't installed it. I purchased a new machine and haven't looked back.
Once you decide that you have to start using Windows 10 (either on your existing computer if it's possible, or on a new computer if you have to buy a new one), I suggest you post back here so that someone reliable can run through the process you need to go through to get your music onto your new machine. Make sure that you understand what I'm saying here: we see hundred of questions here from people who have moved to a new operating system (Windows 10), or bought a new computer (Windows or Apple), who then lose lots of their music that never appears in their new iTunes library. While "moving" your music to a new Library is reasonably easy, it's even easier to get it wrong:
- you cannot simply plug an iPod/iPhone etc. into the new computer and transfer music from that into the new iTunes library
- once you sign into your iTunes Store account from your new Library, only the music you purchased from the iTunes Store will appear in that library (by you downloading it)
- music in your current Library, from other sources (such as CD, Amazon etc.) will have to be "moved" (copied) from the old machine, onto the new one
- the only way to preserve your Playlists (get them into your new Library) is to copy the entire music folder, which includes the crucial iTunes control files, from the old machine, onto the new one. Even then, the process may not be a smooth one
- in addition to the point about Playlists (above), the only way to preserve Play Counts, song ratings and Last Played times is to transfer the iTunes control files as well as your music
So what do you need to do now? Answer; back up all your existing music onto an external drive. It's in your own interest to back up your music, even before considering changing computers. So if you don't currently backup, start doing so now. (Advice can be offered.)