If right-click on desktop/folders is extremely slow and you are on NVIDIA drivers
From www0.org - a collection of sites
It's probably the context menu items of NVIDIA (for the link to open the graphics settings). To remove them:
go to HKEY_CLASSES_ROOT\Directory\Background\shellex\ContextMenuHandlers\
and remove NvContextMenu and NvCplDesktopContext dirs (right-click->backup on ContextMenuHandlers dir before that to bring it back to normal if necessary)
I won't go into more detail 'cause mismanage may be damaging.
Use a shortcut from the control panel to open the nvidia settings. If you want the right click link back, restore the registry entries.
Instant opening!
Optionaly:
To add a healthy shortcut in the right-click menu:
go in HKEY_CLASSES_ROOT\Directory\Background\shell\
right click -> New > Key and name it to the link, e.g. "NVIDIA settings"
go in "NVIDIA settings" and again New > Key and name it "command"
double click on the (REG_SZ-type) value that is already in "command" and give it "nvcplui.exe".
done.