Asus EVOLUTION P5E64 WS - Manual (Page 38)

2-12 Chapter 2: Hardware information
5. Rotate each fastener clockwise to
ensure correct orientation when
reinstalling.
Narrow end of the groove
The narrow end of the
groove should point outward
after resetting. (The photo
shows the groove shaded for
emphasis.)
Refer to the documentation in the boxed or stand-alone CPU fan package for
detailed information on CPU fan installation.