Windows 7: Windows 7 can't left click on start up etc

Hey guys, not sure if this is a hardware or software issue so unsure on the correct forum, but I've had this problem for a while now and haven't found a solution. I just tried putting up with it for a bit and then searched for a solution but found nothing so I kept putting up with it but now it seems to have gotten worse. Here’s the symptoms:


- Can't click start bar on start up and have to press ctrl+alt+del and then click cancel to get response




- If I'm watching a video on YouTube or any other side that is displaying a video if I've clicked in the space around the video (for example to scroll through comments) I can't click on the video again to pause, play, change volume etc. until I click anywhere on the start bar or ctrl+alt+del again.



There's definitely more but those are the most common and freshest in my memory.
I’ve tried different USB ports for my mouse, I've tried running a registry cleaner and turning off start up services, checking for mouse driver updates and so on so I’m not sure where to go from here! The thing is it didn’t happen after I installed any software, it just seemed to start out of nowhere so any help would be great

Thanks