Outlook is slow in opening

Last year we had Wins 98 op sys and Outlook 2000. This year they installed Wins 2000 Professional, and we still have the same Outlook 2000. When we had Wins 98, Outlook would open right away. With the Wins 2000, it seems to take at least a minute ormore after clicking on it before the application will open. Any suggestions for getting it to work better/faster?