Ok, I have a windows 8 computer and have in the last month or so updated to 8.1, I experienced the same problem I am currently having now with my controller as when I first updated to 8.1 but I managed to fix it by finding and manually installing the driver that had somehow been deleted off my computer. Now it's not working again months later, whenever I plug in my receiver and try to sync my controller to it both lights just keep flashing no matter what order I push the sync buttons in. I have tried restarting my computer and changing the batteries. I went in to my devices on my computer and apparently the driver for the controller is no longer there, I have tried manually installing it again, but i can only find a version for windows 7 and my computer errors out when I try to install it. When i troubleshoot my drivers it says there is no drivers for the device and it wont recognize my receiver at all. I am at a loss as to what to do, I was using this same controller just a week or so ago and it was working fine!