From the screen shot I can't see what the Image Zoom is set at on the bottom. Have you changed anything on your computer recently?
I had this happen to me a long time ago. But honestly, I do not recall what exactly I did to correct the problem. Well more like what Thom had me do to correct the problem. I wish I could pull it up out of my memory banks.
It does seem like it was a Windows related issue. (Now don't quote me for sure) You might go ahead and do a Disk Cleanup, scan the hard drive for errors and defrag. I pulled up the microsoft technical help for the issue and that is the first steps recommended to correct it.
I am truly sorry I have not been much help. From the screen shot it looks as if you should be able to simply drag the bar back across the page to the right.
Let me know if the normal computer maintenance has any affect. At least we have really tried today.