I am using all the three office version 2003, 2007 and 2010 Beta simultaneously and found no problem or compatibility issue. Although office 2007 and 2010 have more feature than 2003 and 2007 respectively and they all are properly updated autometically. If you have speed issue then install only required suit like Word, Excel, Power Point only and try. H
Yeah I did when I tried them both together. I think I will install Win 7 Home Premium and Office 2007. I need to tweak it a bit more this time to make it as "snappy" as XP on my netbook.
Outlook is automatically changed with advanced version e. g. when I have installed 2007, the previous 2003 was removed and the same with outlook 2010. I have only one account with google to connect with outlook. When I have to again configure outlook 2007 after its first installation but the same was not required by outlook 2010. There is a little bit difference in appearance of application in each version of office. an excel file can be saved with 97-2003 format with newer version but how it would be appeared and used in 2003 installed machine, the older version required. Some time office 2007 shows compatibility issues but the nature like colour / font / style etc is not specified which actually has the compatibility issue. and this is the only cause to have older version with the new. hence subject to these issues there is no room for office 2003.