Mouse stutter with Flash generated slides.

Yeah, that's a nice laptop.  That shouldn't really be happening.

What you're describing sounds like some kind of resource contention.  It *could* be disk access, but there are some easier things to probably check, since I'm guessing you probably don't have extra hardware laying around.

If you just got it, and it came with a built-in virus scanner, or your work installed one, then it may just be busy doing it's first comprehensive scan of the system.  Same goes for any backup software that you might have installed.  Just letting it do it's thing for a few hours should let any of those scans complete.

Since it's been a day since you posted, you should be clear of that window at this point.  If the problem persists, then it's probably time to take a look to see where the resource contention is.

If you open up task manager (just type task manager in the search bar) and click More Details, what's the CPU utilization?  I'm guessing it's in the 99% range.  If you click that column and sort descending, you should see the processes that are using the most CPU on the system.

My intuition says that if you watch it for a bit, you'll see something pop up to the top every few seconds that coincides with the lag in mouse movement.  You can actually look at the Performance tab too, just to get a sense of what's going on.  If you see that graph hitting the top of the chart (100% utilization), you're seeing evidence that the system is constrained by the availability of CPU time.  Ideally, you'd want to see that chart stay low, particularly when you're not interacting with it.

In this same vein, if you're seeing 100% disk, and/or memory utilization, that would be problematic.  If you're running out of memory, the system is going to "swap" data in memory to disk.  The disk is about 100K times slower than "real" memory, so you'll see a huge performance hit (and a lot of disk activity) if the machine is having to swap and retrieve memory from disk constantly.  Again, if this is happening, it should be pretty clear from looking at the performance graphs.

Microsoft support has a decent guide to improving overall Win10 performance.  There are some UI animations and things that you can disable to reduce overall system load.  You might also take a look at the bundled apps that Lenovo includes, to see if there's anything that's running persistently in the background that isn't necessary.  There are some instructions on reducing the number of applications that launch at startup that would be applicable to that problem.

Windows generally tries to download and apply patches when you're not actively using the system, but you might also just run Windows Update to make sure that anything that's pending is installed, just to rule out that there's background update activity happening that might be exacerbating the situation.

https://support.microsoft.com/en-us/help/4002019/windows-10-improve-pc-performance

Apparently your issue is not happening in Flash environment but also outside your browser right?

I suspect something wrong with your Hard Drive controller. Try to swap your Hard Drive with another and test again.