Windows 7 upgrade causes power button problem

Hello,

Sir,
I have a laptop windows xp now it installed windows 7, But now it showing a problem (ex.when i push power botton for open it, it open a few minute again off automatic, for 3/4 time i open but it auto off after 3/4 times tying then it going on) when xp then all ok. when windows 7 show problem then i going to change it windows 7 to windows xp but same, so i again change windows xp to windows 7.