Parts of desktop keep becoming unresponsive

Right so here is the issue.

For a week or so now parts of my desktop become unresponsive.

For example I might be using Firefox and click on a Word doc tab I've got open at the bottom of the screen and get no response.

Or I might click on 'show all history', get the pop up, and then when I click on a item on it, it goes through and click on whatever under it on the page.

Also when I'm reading manga online I can click page select and bring up a list, but when I click a page it click the internet page under the list instead.

Interesting bringing up and closing task manager seem to make a item responsive again, but it's very much a temporary fix that doesn't last... and a increasingly annoying necessary to get anything done.

What kind of problem am I dealing with here, is something hardware wise breaking down, or is this a software issue?

Parts of desktop keep becoming unresponsive