Done that, but no big improvement? Well, you probably have picked the wrong junk files cleaner, which didn't help you scan and clean all unwanted files.
In such case, you must have been told to speed up PC by cleaning junk files.
That is because the junk file on your PC has accumulated over time, and starts to harm its performance. After you use the windows computer for some time, you may start to feel that it's getting slower.
