I may be asking for an impossible solution, and feel free to let me know whether that's the case. Here's my situation (skip to TL: DR if it's too long): My trusty iMac (Mid 2010, iMac11,2) is still running OS X 10.6 Snow Leopard. It's always been quite stable, and I have Windows XP Professional installed via Boot Camp, specifically for running Cakewalk Sonar 5 (I disabled the network drivers in XP to prevent viruses). Sonar 5 can't be run reliably in any newer Windows version; I invested quite a bit of money and musical effort in it, it's the center of my music rig and I'm not ready to give up on it just yet. My iPods and iPhone sync to the iTunes library on this iMac. However, Snow Leopard's last compatible iTunes version is 11.4; if I get a new iPod or iOS device, it won't be recognized. Also, my iPhone 5 is stranded on version 8 because of this; I tried to upgrade to iOS 9, only to have iTunes refuse to recognize the iPhone anymore. (Luckily, this was on the release day of iOS 9 or so; I was able to downgrade to 8.4.x before Apple stopped signing that firmware). I'm confident I can upgrade the iMac to macOS Sierra easily via the App Store. What I'm worried about is whether the XP installation will be wiped out by the upgrade; if it is, Sierra's Boot Camp won't allow reinstallation of XP. TL: DR version: Does the upgrade from an older version of OS X to the current version of macOS ruin any Boot Camp installations of Windows XP?