excel 2007 Not Responding
 

i' ve office home & student 2007 (en)
when i close to my excel2007 file generally,

first time, Microsoft Excel non-commercial use .... (Not Responding)
after, Microsoft Excel has stopped working (close program).
i can using my excel file but again...

i' ve windows vista ultimate business, nis2007, xps m1210.
(i think, everything is good but office2007?)

what is problem, help pls.
thanks.