Lighting problems

Hi everyone!
I've recently bought a new laptop, and some strange things have been happening with my project. It's something to do with the lights.
This first image shows how simple light cookies aren't working properly:

And this other image show a weird thing some lights are doing, where their radius can be seen as a black silhouette behind other objects.


I'm assuming it might be my laptop (it's Windows 8 64bit, Intel® Core™ i7-4500U, NVIDIA GeForce GT 740M) seeing as both the editor and the builds appear to have these problems :/

Any idea what it could be? Would updating Windows to 8.1 fix it maybe?

Thanks for your time!

PS: I'm using Unity 4.3.3f1 Pro

 

Here's another example of what I'm experiencing. This time, it's a spotlight:

 

Nevermind! Updating to Windows 8.1 seemed to fix the problem!