Overclocking a netbook or laptop is a thoroughly bad idea. These systems lack just about everything required for safe and effective overclocking. One of these being heat which is often a problem even at stock speeds. Manufacturers are well aware of this and leave out the necessary settings from the BIOS. This saves you from failures and them from the resulting warranty claims.
While it may be possible to overclock a netbook the results are unlikely to be satisfactory and the risks high.
Overclocking is best confined to home built systems where you control the specifications and quality of the components used.