You might not be able to get an upgraded version of MSReader for your device, but you should try here just to be sure
http://www.microsoft.com/reader/downloads/ppc.asp
If you want to be able to read the books on your Jordana, you might find a tool called convert lit will help you. Do a search for "clit.exe" on the web. We are not allowed to discuss this product in detail as Microsoft don't approve of the tool ... so don't ask any more questions about it :-)