My calendar page will not load on my desk top but loads normal on other computers. Outlook, Sky Dive & People load normal on my desk top.

The screen is just white. I clicked on properties in Calendar and  looked at the address . It is different from that that shows on the other computers. I tried to change it but it will not let me? I don't know how it changed it the first place as it has worked fine for over a year and now it does not. Any suggestions?

Thank you!