When you boot via the Safe mode you are using the Microsoft default drivers.
That implies that you probably have one or more bad drivers.
Suggest you download/install this (free) program... http://www.phyxion.net/
While booted into the Safe mode, run this program to remove the NVIDIA drivers.
Once you have removed the NVIDIA drivers, make sure all the NVIDIA folders are also deleted from your C: drive. Reboot normally.
If you have deleted all of the sources of the NVIDIA drivers, then you should be able to boot so Windows uses Microsoft's default video driver. If this indeeds happens, then do you still crash?
If you no longer crash while booting normally, then it was a bad NVIDIA driver.
If you still crash in normal boot, then you still have a bad driver,
but lets cross that bridge if we come to it. Good Luck.
I have reinstalled the OS like 5 times.If i dont install the nvidia driver then it does not crash giving a blue screen.This is a very strange issue.and i have installed the driver from nvidia's original site itself...