What is the native resolution of that TV? Make sure the graphics card is outputting at that resolution. Stationary pixels (typically called "artifacts") often indicate an overheated or defective GPU, but as far as "moving" pixels are concerned, I'm not sure what might cause that other than interference or a bad cable (or adapter).
This is the specs on my TV:
I just changed it to that and it looks worse & the TV said "Resolution Mismatch."