New life for old XP

I have some old apps that I run in a Hyper-V virtual machine on XP... I also use XP for a dedicated Web browsing VM (if it gets infected, I can restore to a previous snapshot.)

I personally run Windows 8.1 (technically Windows Server 2012 R2) on the desktop because it has some nice security features. However, this is opinion, and likely would be annoying for others.