When I was getting my build together a few months ago, I had to cheap out on my HardDrive because of the flooding making the prices Skyrocket, I then bought a Second Hand Hard-Drive, I have been noticing problems that makes everything on my computer freeze for less than a second every second, This causes abrupt mouse movements and very bad for Gaming, Every single thing is affected. Audio, Internet, Game FPS, Mouse Movements.. It was my first build, So i'm not sure, But do you think it is DEFINATELY the hard-drive, Because I don't want to spend alot of money for a new one, If this one works fine!
More about :bad sectors hard drive causing problems
On processes tab, be sure to click show all processes, and order the table by CPU usage by clicking on the table column header.
You can also add additional columns (menu item "View->Select Columns"), e.g. I like to add I/O columns to see, what processes make many disk operations.