my friend had the same problem on his laptop
it kept restarting and never finished installing the updates!!!
i fixed it for him by using my computer i searched for a start up and repair disk, on the net, and downloaded it, its about 120 mb and its
free, from Microsoft, i for get the site i got it from but it explained to
me to me to burn the start up and repair download as .iso or otherwise known as an disk image, as opoused to like data disk or music disk its called iso any way that's the type of burn u do with the start up and repair down load,
then u have to make sure in ur bios that its set up to boot from cd first as opoused to booting from the hard drive first, google bios start up, if ur confused (to get to bios hit delete button repeatedly the second u turn on ur machine or tab or f11 or f12 or what ever button it says to hit to enter bios usually u see on the screen in the first second of turning on machine)
. any who booting from the start up and repair disk restore ur computer to an earlier time to about a week or so or maby a month or so b4 u first started having the installing updates restarting problem, and after u click restore it takes a while so be patent and it might look like it froze so dont power off after it has finished restoring when u restart ur computer it should work again.
try google restore using start up and repair disk if ur confused
and a tip is in the restore to an earlier time window it only gives u like 5 restore points which could all be in the one day
if u look down at the end of the window ul see a back to previous months of restore points and click back and it should now show u loads more of restore points from previous months