slow down of system

When I right-click on MyComputer and select Explore, it
takes alot longer than usual to display the directories on
my C:drive. If there are 'alot' of files in a directory
list, eg. Program Files, the laptop seems to display the
icons first not associated, then the association is
instigated. This also occurs when displaying the Control
Panel icons.

When renaming icons for example, the egg timer appears for
quite a few seconds before I am able to rename.

I hope that someone can guide me in the right direction to
fix this problem. Thanks alot.