Browsers Keyboard Hangs Frequently A Few Seconds?

when browsing, the browsers (chrome and ie9) freeses frequently a few secs. it doesn't repond on keyboard or touchpad actions: typing google autofill starts to auto fill, gives no extra characters when i type for a few sec and then gives the letters that a had typed (not all)the same with the backspace key. while typing this there's frequently a lag between typing and appearance of characters.pointer hoovering always works but sometimes (frequently it takes a few seconds to change from pointer to "link-hand" in another browser tab a Internet film is running without interruptions.often when i try to scroll with to fingers touchpad, the scrolling pointer appears but scrolling happens after a few seconds.

other programs like write: no problem
anti virus and malware finds nothing

core temp is normal; memtest and hdd test are normal.in task manager performance monitor 2 of 4 ram is used, the overall cpu use is 7% but every approx 10secs the monitor stops for a few seconds, then the cpu use goes to 100% for half a second and the monitor runs again.in safe mode everything seems ok?