At least, this trouble began to be occurred on August 5, 2011.
According to the web information and my confirmation, Microsoft Security Essentials detect the virus called “Worm:VBA/Circ.B” when you login Gmail using Internet Explorer 9 (IE9). And hereafter, IE9 cannot access to Gmail until removing Cookie information.
If your PC happens this trouble, please tentatively use the other web browser like Firefox or Google Chrome.
Please see the following web page if you’d like to know the detail information .
- Googl Help Forum「Worm:VBA/Circ.B warning when I open gmail in IE9」
8th, August, 2011 Chief of Information Processing Office: Kitani