Celeron Overclocking FAQ by Frank Monroe, Page 5 Just the FAQs ma'am. There are a number of things that could happen to your system through overclocking but, with a little common sense, you can remove most of the risk.
Heat is the primary concern.
The CPU is the system component that is most likely to suffer from excess heat. Keeping the voltage as close as possible to the default of 2.0 volts and using a quality heatsink and fan will keep the CPU temperature within reasonable limits. Long term effects of higher current produced by faster clock speeds can have more subtle effects. This is a very slow process and it takes years. A modern CPU has a design life of 10 to 15 years.