Copying things and replies

I am having problems with MS Outlook when I try to reply to a message
with more than just text; it just locks up Outlook and doesn't do
anything but give me an hourglass. The same thing happens when I try
to copy things off of the internet and insert them into a message to
send. I am pretty sure I don't have a virus, but don't know what else
could be causing this. Any suggestions would be appreciated.
Otherwise, for normal formatted type messages, it works fine.