Slider was set to the lowest setting, which isn't something I would have changed and certainly haven't always had the problem. Moved it to the top position and it's remedied the issue, thankyou.
Opened Task Manager because the system was running slow- Is it usual for Malwarebytes Anti-Malware (32 bit) to be using almost 200mb of memory? Also Disk is running at 97%+, with nothing clearly using excess amounts.