You can easly make a private server on windows 8.1 the same way as making it on a windows 7, you install SQL 2012 and then download omega files or whatever files you want.. run the BAT file to install the server & the database files will auto update to your current SQL server information.
Then do the normal stuff you do like it's a shaiya pv server on windows xp or 7 or whatever you want, just make sure to run everything as admin and give yourself admin privileges before starting anything.