Please help..

Hello! im a newbie here in the sevenforums.. badly need your help.. i have Samsung laptop model:NP305E7A-A02US Quadcore Processor, 500HDD 4G RAM Windows 7 Home Premium SP1. the problem is, when i turn the power on it just display starting windows for 2hours+ after that the blue colored screen for let say 2hours then went back to launch startup repair or start windows normally.. i already did the bios settings to press f9(optimized defaults) then f10.. thats my problem sir for almost a week now. is there any speacial key like smartphones to reset the factory settings of my laptop? please help..
Thank you so much.. have a good day!

Boot into BIOS setup by tapping the key given on first boot screen, is the HDD detected?

If so run Startup Repair several times with reboots, preferably from DVD or Repair CD. Report back results.

If that fails start at the top to work through the steps for Troubleshooting Windows 7 Failure to Start which lead up to if necessary running Samsung Factory Recovery from its partition or disks, or getting a superior Clean Reinstall - Factory OEM Windows 7.