I know that istalling on dual boot in order: Xp installed first, then W7 or W8 is no problem.
But i am using W8 Enterprise about 40 days, there is a lot of programs installed and i am not very happy to install all again.
I found instructions how to install XP on dual boot with Windows 7 already installed, but no instructions how to manage this with windows 8.
I have a few programs that not work well in Windows 8 or some not work at all.
Now i am runnig dual boot W8-W7, W7 installed after W8.
It is work OK, but it is only partialy succesful, still some programs not work properly in W7