Also, have you extracted the downloaded files correctly. Try writing them to a new folder (don't overwrite the old folder). We've had failed extraction before, which has stopped SE from starting properly. You should see this folder structure after extraction is completed:
Your folder size on your hard-drive should be ~415Mb after its extracted
Quad Core i7 930 CPU o/c 3.8 GHz - 6GB DDR3 1600MHz RAM - ATI HD 5870 1024Mb - Intel SSD X25-M Gen 2 - Win 7 64-bit Add Your PC Spec To Your Signature Or Post It Here