Internet Explorer 7: phishing filter slows down computers
When you visit some websites in Internet Explorer 7, the integrated fishing filter can slow down your PC by hogging the CPU. The tool is designed automatically to protect users from websites that try to get personal access data by pretending to be a different website. If the website contains a lot of frames or if the viewer opens up a lot of sites at the same time very quickly, the monitoring that goes on in the background can apparently detrimentally affect the PC's performance.
While Microsoft already provided an update a few days ago, it is not automatically downloaded via the security update function. If you are having the trouble described above, you should visit Microsoft's homepage to download and manually install the update.