Well I downloaded FireFox as some of you instructed and I still couldn't open my yahoo e-mail.

A friend told me that I needed to do a back up on it. He told me to:

Restart notebook
Push F5
Push F8
Choose 'Safe Mode With Networking'
Click on 'No' on the desktop message
Choose a date from the calendar of the LAST day that I remember it working properly


Does anyone know if this is a good idea?

Thanks to everyone for your help.