System cannot recognize HDD and CD Rom together

[littleT]

i have a friends computer ----it will not find both hhd and cdrom at same time.want to reformat computer however only 1 connector ide i guess works -the other finds nothing.if i connect hhd it finds it--if i disconect hhd and connect cdrom and restart it then finds cdrom if i connect both on same cable it only sees 1 of them help please oh yea the system was not booting all the way when he brought it--it said no operating system found

[Birdie]

After plugging a secondary disk to your Windows computer, the primary disk does not appear in the BIOS ( Basic Input / Output System ) or My Computer. This problem may occur even if you do not hit the main disk when you connect the secondary drive . As a remedy, you can try to detach the secondary drive . This method works in some situations and may solve the problem. Persists , connect your main drive to another computer healthy , that same version of Microsoft Windows. Here you can find this drive is not visible in my computer but it shows in Disk Management . The reader may show that the RAW file system and disk space as unallocated whole . In such cases, you should use CHKDSK to fix any damage to the hard drive.