Here are backgrounds that you can use for your MSN conversation windows.

To use a background, save it to your computer. Then, start MSN Instant Messenger and while you're having a conversation with someone, click the "background" icon on the window (it looks like this ). Click "more" under the "My Backgrounds tab and then "browse" in the window it brings up. Find the location where you saved the MSN background and then double click it. This will add it to your backgrounds list. If you want to set it as your default background, highlight it and then press the "Set Default" button and you'll be all set to go. Enjoy!