outlk express 6 can’t open links in email

When ever I try to open a link in my email using outlook express 6 I get an error message. The message reads….The program must close to allow a previous installation attempt to complete. Please restart. I’m running XP and scanned the computer for viruses…none found. I’ve restarted the computer and no help. Can anyone help me determine what’s causing this error?????

Thank You