I have an Acer Aspire V15 Nitro with 16GB of RAM, an i7-4720hq at 2.6Ghz, and a Geforce 960m with 4GB of vRAM running a 4k windows 8.1 environment. I am experiencing lag in the oddest places: the lock screen when I click and the picture slides up to allow me to type in my password, and when I click and drag the mouse on the desktop or in file explorer to select a large number of files. The blue highlight box lags behind my mouse when I move it. Occasionally my mouse will also lag significantly in general whether using the trackpad or a wireless optical mouse. When this happens dragging windows (like chrome and Word) around is also slightly choppy. I have set the max/min page file size to the "recommended" value, set the default graphics processor to the 960m instead of the IntelHD 4600, and have restarted windows in 1080p to no avail. I even have windows and all programs installed on a SSD. CPU usage rarely goes above even 10%, and Memory rarely above 50%. Disk usage is also usually zero unless I am copying files or something similar. I do not understand how I can run Half Life 2 and Fall Out 3 at 4k above 40fps on max settings but have the system lag when scrolling up a picture on my lock screen. It is very frustrating because I spent quite a bit of money for these kinds of specs. It seems to be able to handle very demanding tasks effortlessly but struggle with the simple ones like the 7 year old laptop it replaced. Any help would be greatly appreciated.