Ok. My computer is always plugged in, and I never run on batteries ever. Even after rebooting several times, my CPU speed remains 2.8. I just tried running CPU-Z to be sure, and yes it displays my speed as 2.8.
It seems my CPU was downclocked. I am not aware of any method to clock it back up to 3.6 GHz. Can anyone help?
What BIOS version are you currently running? Also try right clicking on My computer > Advanced > Click on settings under performance > click on Data Execution Prevention. If you could screen shot what you have there and post it up that would help too.