What is the new HD jumpers set as...Master?
Take a look in Bios and see that your new HD is set as first in boot order and Save and Exit
here are the usual keys for entering Bios to press on startup.
- {Delete} (modern Award and AMI BIOSes)
- {F2} (modern Phoenix BIOSes)
- {Ctrl}+{Alt}+{Esc}
- {Ctrl}+{Esc}
- {Alt}+{Esc}
- {Ctrl}+{Alt}+{S}
- {F1}