Browser does not show changes in JavaScript. It keeps the old version

Im working with: Chrome Codegnitor (PHP) XAMPP CSS and JS My problem is: When I do a small change in CSS or JS (any simple, trivial change), the browser does not show this change. Only when I rename the CSS or JS file it shows the change. Its looks like the browser remembers the old version of CSS or JS and does not "go and look for the changes" when I reload the page in Chrome. Any idea what is holding back the browser? I've been searching for a question, but found only people whose browsers do not take jS into consideration at all. But my browser does. It deos load JS, but not the changes that I make. The funny thing is that a week ago I needed to rename CSS and JS file once or twice a day, but now I need to rename it when I make any change to see that change displayed in the browser. So it is imposible to work. Someone having the same issue? P.S. I'm having the same issue with Mozilla nad IE. So I guess somthing could be wrong with my computer. Could it be one of those security programs. I've got one with FileZilla two weeks ago but I thought I've got rid of it. Maybe it is still making the mess in the background.