I am using a H55-P33 MSI Motherboard with a Corsair 600 GS SMPS, ATI Radeon 5770 HD 1GB GDDR5, 4 GB Transcend RAM and 1 TB Seagate Hard Disk. Recently, when I used to play any games on my pc, it suddenly used to shut down after sometime and when restarted both the fan of motherboard and graphic card were not rotating but my SMPS was working fine. Then I pressed the main cable from the SMPS to the Motherboard down a bit, the fans used to rotate but, pc didn't used to boot. So I tried my old pc's Hard Disk and it started booting, then when I used this new Hard Disk it worked fine then again after sometime it used to be the same problem again. This thing continued for 5 days now it works ok but everytime I shut down my pc and turn it on later it gives "NTLDR is missing please press Ctrl+Alt+Del to restart" message and when I press the keys the pc works, what is this problem? please help me with this.