|are you using the same installation dvd? try another...|
did you check the event logs?
if it runs in safemode, it has to be something thats starting up in the full version a driver or program.
remove all unneccesary startup programs, type msconfig in the search, go to startup uncheck everything but microsoft.
try to startup again.
make sure you are not connected to the internet, when you startup.
are you sure your system is not overheating, check your cooling and heatsink is properly connected to the cpu.
finally install win xp, and run a win 7 compat test
i hate computers!
but cant help myself....