Microsoft has been haunted for years by the ghost of Windows XP; now Microsoft is releasing a big batch of case studies and research aimed at persuading its largest customers to move to the new Windows 7 operating system, with a message “Get over it! There’s something better out there for you!”. Last week, the Directions on Microsoft Research firm issued a warning about the complexity of the volume-licensing agreements. Microsoft is hoping that Windows 7 will help convince customers that there’s still value in the deals. “What we’re really doing is saying, ‘Hey, you own it. Deploy it, and get off of Windows XP. Move on,” said Gavriella Schuster, a Windows general manager, in an interview last week. “Throughout Vista what a lot of customers did is they brought new hardware into their environment and then they standardized back to XP. It’s like, don’t do that! Run a heterogenous environment for a bit, until you get everybody on 7, but you’re going to save money when you get everybody to 7, so try to get there as soon as you can,” reports.