what av are you running? i had a issue like this the other day on a freinds systems and i had to remove kaspersky and then it worked perfectly just a thought
Have you tried running slic dump toolkit just in case you have a retail version of windows i very much doubt it though also make image of your retail ultimate dvd with ultraiso then delete the ei.cfg file from sources folder and burn dvd. no you should be able to install and use oem slp key and certificate.