I have a dell gx280 i installed win 7 pro 32 bit in it today it works fine then when i turn it on again its shows an error drive 1 not found:serial ata,sata-2 drive 3 not found parellel ata,pata-1 (pri ide slave)stike f1 to continue f2 to run setup utility.i strike f1 then it shows NTLDR is missing press ctrl+alt +del to restart i do as it say then shows same drive 1 etc.what is the solution.