Using Internet Explorer was very risky for the last few days due to the recently discovered bug.
Unless you solve this problem, please do not use Internet Explorer.
To solve the problem, just go to Windows Update in Control Panel and Check for updates – apply all critical (recommended) updates NOW.
For details see this article http://www.theregister.co.uk/2014/05/01/internet_explorer_patch/
This patch is available for Windows XP as well.
Windows Update settings
Go to Control Panel – Windows Update and make sure it is set to automatic checking and installing updates.
You may temporarily want to disable this setting when you are in very low bandwidth places. But remember to put it to automatic whenever you are back to home or office.