|Likely, you won't be able to upgrade the CPU, but depending on how much memory you have, a RAM upgrade may help. Other ways would be the same as improving speed on a desktop (you can Google that)...|
From the owners manual (Sony PCG-FRV27):
Why does the System Properties dialog box display a slower CPU speed than the maximum?
This is normal. Because your computer's CPU utilizes a type of CPU speed controlling technology for power purposes, System Properties may display the CPU's current speed instead of the maximum speed.
If the speed control is active (and the source of your slowdown), and there's someway to disable the speed control, that might help slightly, but at the cost of shortening your CPU's life...