CPU Speed Test
Here is a piece of software; CPUIndex (small - about 4KB) which I received by email from someone who sends me good stuff occasionally.
I don't know who belongs to this program and there's no copyright notice to read or write about.
After downloading the file, you use the Start -> Run to 'run' this program. What it basically does is work the Processor for a fixed amount of seconds and return the result.
Just to to get your feet wet, here's something you can try.
By the way, you've also just tweaked your Windows/PC to work faster.