Pen drive recognized but not acessible

i hav Hp pavillion dv2713tu notebook,
i'm not able to acess any pendrive on my pc,


my notebook detects the pendrive but wen i open it
the msg displayed is

acess is denied

H;| is not acessible....

i also formated it on my frnz pc,but still it is not accessible..
but my pendrive is acessible in others pc



please anyone help me out wid dis problem...