PC Detecting slave drive as main drive

[Guest]

I have an old hard drive that I have tried to install into my 'newer' computer. Both are IDE so this was not a problem. However the strange thing is that once installed the slave drive is detected as the main drive and the main drive is no where to be seen. I tried swapping out the cable connections and then the ie putting the slave connection on the main drive. This resulted in the main drive being picked up as the slave but no main!! Any ideas would be greatly appreciated.

 

[MrLinux]

Check the jumpers on the drives, they either need to be set to Master & Slave or both set to Cable Select.