I just installed a second HDD to my PC. Meanwhile I realised that I had both RAM modules on the same DDR channel and therefore wasn't using DUAL channel memory. So I pulled one out and moved it to the other chanel. Then I powered up the PC and got a load constant beeping sound coming from the PC speaker...and the system wouldn't boot up...
Since then I have removed and put back the memory and rebooted and its now working....but what was it? Did I overload the power supply with the extra HDD (IT's a THERMALTAKE Soprano case with only 1 Pioneer DVD burner, FDD, 1 x SATA HDD and 1 x IDE HDD.