Desktop Intelligence *.rep Files Opening In The Same Window

Hello,

We are running BusinessObjects Enterprise XI 3.1, the version of the Desktop Intelligence client we are using is 12.7.1.2131.

A problem we have encountered is if you double-click a Desktop Intelligence document (*.rep) on a Windows 8.1 Enterprise machine, it always launches in the same instance of Desktop Intelligence that you have open.

However if you double-click a Desktop Intelligence document (*.rep) on a Windows 7 Enterprise computer it always opens a new instance of Desktop Intelligence.

Most Windows 8.1 Enterprise users want every Desktop Intelligence document to open in a new instance.

Is anyone able to advise what setting is controlling this behavior? I cannot see anything within 'Tools' -> 'Options', so I'm wondering if its a registry key.

Thanks

Stuart