Apple's support is no longer great! I've been on hold to get this question answered and I've been pushed up to the third level. I bought a new iMac 21.5 inch in 2015. I later found out it was manufactured in 2013. Anyway, my simple question is can I use this iMac as a display for my PC and how do I do it? I had a new PC built this year and it is powerful and full of features I need but I still use my iMac for photography and to coordinate all my Apple devices. Thank you for any help.