When using Outlook, my Word is hanging when I try to reply or send an email

Microsoft Word 2003 SP1 and Windows XP Professional SP2 Version 2002 on a HP laptop, 1.73ghz,504ram.

When I try to send an email or reply a box opens which says “Starting Microsoft 2003 as your email editor” but then it just hangs. I then have to crash out of it. I also can’t open Word attachments in emails. However, this morning I drove to the Computer shop, turned on my laptop and it decided to work properly. This problem seems to be intermittent.Please help me as I work by myself from home and am sooo frustrated.