How many small dots? Are they in a specific pattern or is it random each time? Is your screen an HCPD compliant screen?
Check to see if you're running the current version of your Video Card drivers. It may be something as simple as that. If you're running off the drivers from the windows update, you may be behind a bit.
If its not drivers, it may be an issue with your hardware. Easiest to check is plug in a different monitor, or in to a TV if you have the ability. Also try swapping out the video cable.