The WD Scorpio Blue 750 GB and 1 TB uses the the new Advanced Format sector size but it only works natively in Windows 7, Vista. XP requires a software fix. The 1 TB drive is 12.5 mm thick but the 750 GB is only 9.5 mm thick. I have the WD Scorpio Blue 640 GB HD in my router and it is only 9.5 mm thick as well and it works perfectly. I am not sure that the 1 TB will work due to it may be to thick to fit.