laptop window's with "application blank"??????!!!

[marryme]

Hi guys!! i try to close a window while on the internet, but sometimes it won't let me, and if i try click on the corner "x" nothing happens, so only way i can get rid of the window is minimise it and then restart the laptop again?? also it freezes when it's in the mood (happened twice).. and takes me a few start ups and restarts to get it right again.

Hope u understand my terminology. But how can i rectify this problem????

thanks for your help! =*