Your specification looks reasonable. Sometime, mis-assembly of hardware configuration can lead to problems but in your case I do not find any such problem. Since, you have not done overclocking also; an error at that end can be ruled out.
What I currently want you to do is reset your CMOS. After which remove your RAM, wipe it on a soft cloth and reinsert it. Check if the system boots, if it does, the first thing that I want you to do other than taking back up is to follow the following steps:
Type ‘Event Viewer’
Run the application you get in the results
Note down all the errors and warning message you get in it.