opening excel file in different stations

Hi,
I linked an excel file to my website.
There is a problem opening the file in different stations/computers.
in the first staion, it works fine , it can be open as an excel file,
but in the other station in opens the file as a compressed (zipped) folder and then when I press the "open", It asked to save the file.
there is an attched file so it will be more clear.
can someone tell me why it works like this? what is the different configuration between the computers that causes the file to open differently?
how can I solve it ? so it will open the file as an excel and not compressed (zipped)
hope you can help it's a big issue,
thank