The good news is that you have a lot, or perhaps all, of your music on your iPhone. We can’t help you about getting your computer back up and running in this topic if the initial reboot isn’t successful. However, we can tell you about how you can get your music back from your iPhone to your iTunes app, once your computer is running again!
So, if your only copy of your music, videos, and other content resides on your iPhone, iPod, or iPad, then you need to use a third-party tool to copy your music from that mobile device back into iTunes app on your computer, once you’ve got your computer up and running again.
Do a web search for "copy iPhone or iPod to iTunes" and you will find a number of both free and paid software tools to accomplish this task.
We recommend using a free trial of any software before purchasing it to make sure it will meet your needs.
This solution will also help if you encounter the problem where all your iPhone music is grayed-out when you view it from iTunes. In that case, you will need to copy all your iPhone music to iTunes, then start fresh with the sync steps or manual transfer steps described in topic 3: "Sync Your iPhone with iTunes."
CAUTION: Please do not use this third-party software to create unauthorized copies of music, videos, or other content that you have not legitimately purchased.
