In Windows XP, when I right-click a file or folder, sometimes my CPU goes up to 100%. Why?
MS KB Article 819101 has more info:
In Windows Explorer, when you right-click a file or folder, you may experience any of the following behavior:
Any file copy operation that is occurring at that time may appear to stop responding.
Network connection speed may significantly decrease.
All streaming input/output operations such as listening to music on Windows Media Player may become distorted.
When you right-click a file or folder in Windows Explorer, the CPU usage goes to 100 percent while the shortcut menu is displayed. It returns to the correct level when the shortcut menu is closed.
To work around this behavior, use either of the following methods:
Turn off the transition effects for menus and ToolTips.
To do this, follow these steps:
To turn off the transition effects in Windows XP do the following:
Click the folder or file that you want (select it) before you right-click it to display the shortcut menu.