I have a Dell Inspiron n7010, intel i5 460M, 500GB, I install to my external but eveytime it gets to the grey boot screen in restarts. I have tryed -v, -x, and others but still nothing. I need it on my external

The restart occur when you try to boot the install disk or when you boot up your installed system from your external drive?

You've used any Distros? Try booting with -x -v cpus=1

Well, I used iATKOS L2 and also S3 v2 and also iDeneb 1.4 and a few others but it reboots after being installed.