C drive with OS is working fine, having difficulties adding 250GB HD. Have been helping him by phone.
Plan to visit tomorrow to install Bios update and look at other minor problems but have talked him thru Maxtor 250 HD install to the best of my abilities with no luck. Cable connections master/slave all sound correct, bios settings SATA +PATA, etc. OK. Thought driver update would help, guess not.
Will know tomorrow. Really, thanks for the help.
Really old post but the problem with adding a second IDE PATA drive is that it is probably not set up as a slave for the secondary IDE channel. A two drive system on the same cable needs to be one master and one slave. See the tiny connector next to the power. This post is FYI for future reference.