Windows blue border be gone?

[Varen Swaab]

Hello everyone

I'm wondering if there is any way to remove the lovely blue border 
Windows insists on putting around all windows? I know that I could do a 
custom shape window with a mask but that isn't a solution I could use 
for this project. Is there any other way  to remove the border, such as 
a RR setting I'm missing?

Thanks

Var