Outlook Express non-responsive

> Outlook Express is frequently non-responsive when first
> started. When the computer is started and Outlook
> Express is opened, it does open the program but will not
> download the messages.....or it will download them after
> an extended period of time...say 5 minutes or so. When
> the program finally does download its messages (after
> canceling the program and restarting several times) it
> takes much longer than normal (if at all) to open
> individual messages. This problem started about 5 weeks
> ago and has been getting worse with time. It is now to
> the point of not working at all. I have also noticed
> that other programs are now sluggish in their reaction
> time....expecially my real time stock charting service.
> Any idea what might be the problem here? Thanks for any
> help. Windows XP, Home Edition, Version 2002, Intel
> Celeron processor, 695 MHz, 504 MB Ram, 26 Gigs.