apache 2.2 - Latency time to sometimes load css or js file to 5s on localhost

I use windows 7 64 bit + xampp 1.74 (apache)
You can see in this picture:

http://www.pixhost.org/show/2206/6438394_capture.png

all that files is on localhost. it takes 5s to response. i checked
Why is the response on localhost so slow?
but it can't resolve this matter.