It's the site you are browsing in the default starup page of the iexplorer.
The site auto-launches many iexplorer windows, sometimes the cpu may hog!. Do you experience any porn site? It's came a moment that you may have up to 10 or more windows opened.
In order to minimize this, with the explorer closed, left click, properties, startup page, choose BLANK. Start explorer and see what happens...
If in the next boot the start page seems to ber changed, it's not a virus, it's a key in the registry! Search the registry for the first letters of the site and clean every key that may pointed to that site.
How to prevent it from being changed again?
1.- Don?t browse that site (like www.muzikum.com)
2.- Start your windows NT account with a user like profile rather than a power user or administrator account. (Users can't modify the registry!")