Oh dear. That sounds familiar! I've sometimes had to try re-installing ME several times before I've managed to get it to go all of the way. (Try running scandisk immediately prior to rebooting and attempting to re-install). Just once, I decided to bite the bullet and reformat the disk for a fresh installation. Even that took several attempts!
All of this could be related to damaged BIOS. My system gives a 3-1 beep code when I boot (or, occasionally, 3-2) and I understand that this indicates a BIOS fault. I've got two problems here, though. The first is that every computer I've ever owned has started producing odd BIOS beep codes within weeks of my purchasing it. (So, with my luck, if I fix it, it'll only happen again!). The second is that every website I've ever read about attempting to update the BIOS seems to suggest that trying to do so will result in drought, famine, plagues of locusts and the start of World War III !
So, listen to those beep codes but, if they're odd, please find someone more confident than me to help! Otherwise, I can only suggest that you keep trying to re-install ME.
Sorry that I can't be of much real use to you on this occasion. Good luck!
Chris