Endless Vista reboot / Looping cycle step 3 of 3 100% complete

My laptop is stuck in the reboot cycle. Installed SP 1 on my brand new laptop yesterday but I’m currently stuck in an endless reboot cycle step 3 of 3 0% complete. When I run the repair the OS option it does so and then immediately restarts the SP1 install and then reboots after step 3 of 3 100% is complete and restarts … Can’t break that cycle. I have also tried the disk to repair, does not repair and all the menus on F8, F12 (bootable DVD). Tried to use Restore point, says I have no restore points. Safe mode does not work. What the H.. is going on? would appreciate your help.

Nigel