I own a Dell Dimension 4550 running windows 7. I recently upgraded the memory only to be confronted with a black screen with blinking cursor once past POST. The only way i can actually boot into windows is by pressing F12 and choosing boout to utility partition. The bios boot sequence only contains floppy disk, there is no mention of hard drives or CDROM drives. Consequently I cannot boot to the C Drive or the CDROM drive from the F12 menu. I have taken out the battery and reset the CMOS jumpers to no effect. I have tried to boot from a floppy into the CDROM drive so that I can use recovery console- again DOS does not see the CDROM drive. Once in windows though (accessed as i mentioned from the utility partition) all drives work and interestingly in the Phoenix BIOS (which I have also reflashed from dos using a floppy) the hard drives and CD roms are present but as I said not in the boot sequence. I have replaced the cable to the hard drive also and unplugged and non vital USB connectors. Any thoughts?