Windows 8 freezes

hi everyone

i installed windows 8 for third time today it installs fine and everything works
but when you start to use it every 30 seconds randomly it stops responding for 10 seconds but mouse moves then it responds and it happens over and over .
i didnt have these problems with windows 7.
my computer: asus 560 ti ....i5 2500k....ram:corsair 8g 1600mhz ....hdd:western digital 1 tra ....mobo:asus p8z68-v pro/gen3

please help me .it is driving me crazy.
thank you for your help.