ok, i had a old HD (WD 20G, with xp update) and i brought a new HD (Maxtor 60G) with a fresh window xp installed. here is my problem! (both formated)i set my new HD as master and old as slave (the jumpers are set correctly) my computer could detect the setting before and worked fine, and then one day i took my old HD out, then my computer alwayz detect my Maxtor as a slave HD ( no matter how i set the jumper), and when i put back my WD HD as slave, Maxtor as master, my comp doesnt detect the setting and cant start(stop at verifying DMI data...)!! but, when i set the WD HD as master and Maxtor as slave it works fine!! what happen?? how can i set my maxtor back to master!!

Just a suggestion try resetting bios to default.

I have found it impossible to set the Maxtor master/slave jumpers from the information on the drive. Go to the maxtor site below and look up the settings for your drive to see if your settings are correct. http://www.maxtor.com/en/support/products/ata/desktop/index.htm

Some mobo's need the master to be installed with the master HD on the first connector on the IDE ribbon. Try swapping the ribbon connections on the drives. Also, you say you bought the HD with XP installed? The OS has to be installed on the machine it is used on.