Is this on a particular document or any document (new or previously saved)? If it's on saved documents but not new ones, the file might be damaged. If it's on new documents but not older (saved) ones, the preferences might need to be replaced.
It sounds like you are describing Presentation Mode. Normally, you enter Presentation Mode by going to View>Screen Mode>Presentation (or Shift W), but if you are going there by just hitting W, you might want to look at Edit>Keyboard Shortcuts, change the Product Area: field to View, and click on Screen Mode: Presentation to see if it is still set up for Shift W (with the Escape key to exit Presentation Mode).
You didn't mention your OS and ID version...
In Windows, CS6 (ID8) go to Edit>Preferences>Guides & Pasteboard.
Among other options there you can change your Preview Background color.
this worked exactly like you said, thanks a lot