ok, so im kinda dumb wtih computers. i have a dell inspiron 6400, 1GB RAM, 120GB 5200 8MB SATA Hard drive. My hard drive started making some horrible sounds, and someone told me it was dead. I bought a new WD 160GB 7200, 16MB hard drive to replace it. I pulled the old hard drive out, took off the mount and attached it to the new hard drive, and put the new hard drive into the slot. When i turn on the computer i get the error "no bootable devices--strike f1 to retry boot, F2 for setup utility, F5 for onboard diagnostics" i hit F2 to go to BIOS. in BIOS under "device info" it says there is no primary hard drive.. what am i doing wrong? i read that all you need to do to install a replacement hard drive is put it in, and run the Windows re-installation CD which i got with my computer. but when i do this, and follow the prompts to install windows, it asks where to install windows, but the hard drive is not showing up. what do i do??? please help!