Why would hovering over the Windows taskbar unfreeze my applications?

Question

I purchased a Thinkpad 570, downgrading RAM to 4 GB, and from SSD to HDD, so that I could buy my own components cheaper than Lenovo was charging for upgrades.

While waiting for parts, I started using the laptop anyway. It is, expectedly, horrible.

Chrome alone easily maxes out the RAM, and it freezes for a few seconds, every few minutes. If I have YouTube or Twitch tabs open, then literally every 30 seconds.

I assume this is because of paging. But I noticed that once it freezes, if I move my mouse over the Windows 10 taskbar, it always unfreezes the very instant the mouse hovers over. I also noticed this with other applications, e.g. ExpressVPN, Simplenote. And it's not just "coincidence" or seeming like the trick works—over the past few days, I've gotten into the habit of flicking my cursor over to the taskbar whenever an application freezes, because the application definitely wakes up when the mouse contacts the taskbar, 100% of many, many trials.

I'm just curious, if there's anyone knowledgeable in O/S design, Windows 10, paging, etc.: Why would hovering my mouse over the taskbar suddenly wake up the application?

Answer 1

I upgraded to 32 GB of RAM, and no longer have this issue, though I'm still on a 7200 RPM HDD. This supports my theory that it was a paging issue.

I also noticed before the upgrade that my cursor specifically had to be over one of the tasks on the taskbar, for that task to unfreeze. I don't know how to prove this, but my theory is that hovering the mouse over a task initiates a thread to generate a window preview, which in turn places that task at a higher priority slot in the scheduler. Without this scheduler boost, it was stuck in a lower-priority queue due to its having been paged. (Though, I would imagine paging schedulers use some form of MRU prioritization algorithm, so I don't know why the task was deprioritized so much...)