Does anyone know anything about Internet explorer 7? Everytime I am in my yahoo email and want to print?

my email out IE pops up saying : error signature. If I click cancel it wipes my browser away and brings me back to windows. Im still connected but I have to click IE7 again to get back on the internet. I try to upgrade to IE8 But have difficulties as well.any help would be great. Im kinda computer illiterate so explain well please . thanks