I have bought a new external hard disk and i have reformat it as Z: partition. At the beginning the local disk can be open directly with same window without delay in My Computer. But after i remove the local disk and restart my computer, i found that the Z: partition is no longer open in a same window from My Computer instead it open as explorer window in a new window with delay. Besides that, i found that when i right click my local disk Z: it shows this choices

Auto
Autoplay
Search...
Open
Explore

Before that the choices is just

Open
Explore
Search...

I have try before to reformat the hard disk, at the beginning the problem has gone. But after a few restart of my pc that problem has appear again.

Anyone there could kindly please give me any hint or help to solve this problem?

It sounds like your external hard drive is being confused with a DVD/CD drive.

How are you formatting? Through XP?

Are you assigning the drive letter Z?

If so do not assign a drive letter. Let XP call it what it wants to.