I recently just purchased a 650W psu to replace my old 300W as i want to upgrade my graphics card. I followed instructions given to me in the booklet, and looked at many youtube videos to help me through the process. However, when i boot up my PC, i get an error telling me to reboot with proper media, or something along those lines. Basically meaning I don't have an OS to access my computer. Everything else is receiving power, the Disc drive is working perfectly fine, just not my HDD. I have a SATA HDD and the same type of cable is used to power up my disc drive. I'm fairly confident everything is plugged in perfectly fine and i need a solution to this problem, has my HDD broken? Also plugging in my old PSU doesn't work either. Thanks.
Check your setup in bios. And make sure your cd drive is empty.