Q: iTunes floors my CPU on Windows Vista

Close your iTunes,

Go to command Prompt -

(Win 7/Vista) - START/ALL PROGRAMS/ACCESSORIES, right mouse click "Command Prompt", choose "Run as Administrator".

(Win XP SP2 & above) - START/ALL PROGRAMS/ACCESSORIES/Command Prompt

In the "Command Prompt" screen, type in

netsh winsock reset

Hit "ENTER" key

Restart your computer.

If you do get a prompt after restart windows to remap LSP, just click NO.

Now launch your iTunes and see if it is working now.

If you are still having these type of problems after trying the winsock reset, refer to this article to identify which software in your system is inserting LSP:

iTunes 10.5 for Windows: May see performance issues and blank iTunes Store

http://support.apple.com/kb/TS4123?viewlocale=en_US

Refer here for a fix from AVG Support;

http://forums.avg.com/ww-en/avg-forums?sec=thread&act=show&id=190891

You're very welcome. :-)