Triple OS System problem with creating primary partitions

[cameron7410]

I want to have my computer use Windows Vista & 7 & 8.1, but I am having trouble creating another partition to use for windows 8.1

 

[Mr Davo]

In my experience when working with three or more operating systems in a multi-boot arrangement it is (almost) always best to perform all partitioning before putting the first OS in place. Also the order of installation was really important, starting with the oldest OS on the first partition, and steadily moving to the newest on subsequent partitions. Of course in the age of virtualisation one can't help but wonder why you are using a multi-boot arrangement? My advice at this point would be to look at Desktop Virtualization; a free software package like 'VMware Workstation Player', or 'Microsoft Virtual PC' will likely do everything you have in mind and more!!!