My Microsoft Works documents suddenly close?

I have Microsft Works 7.0, and every so often while working on one of my documents, a popup comes onto the screen saying something close to this:

"Microsoft Word has encountered a problem and needs to close. Any information you were working on that has not been saved might be lost. We apologize for the inconvenience and a sorry for anything that might be lost."

And then it asks whether or not I'd like to send an error report. No matter the button I choose, my document closes and what I was working on that hadn't been saved is lost. Only once my document has remained.

This is an extreme problem for me, for I lose very important documents that affect my career.

Why do these popups keep coming back, and is there any way to prevent them?

My Microsoft Works documents suddenly close?viruses

use the "Detect and repair" option in the help menu if you can.