Slow opening folders in Explorer

> Windows explorer (or My computer) takes very long to open
> folders. To open C: under "this computer" takes 1 minute,
> and then to open a certin directory (which contains
> several subdirectories with a lot of files in them) takes
> 3 minutes... While the hard drive is working constantly.
> Opening a program like Nero also takes long because it
> waits for it's directory tree to open.
>
> I thought it might be the Q811493-problem mentioned here
> earlier, so I uninstalled that patch. It made no
> difference at all. So what could the problem be?
>
> Funny enough, I have another drive, D:, whith exactly the
> same content of folders and files (drive moved from my
> old computer) - and when I open folders on that drive
> with Windows Explorer it goes as fast as a click! Just
> like it used to be on my old computer (though it was a
> slower machine than the new one). XP was on both.
>
> The old drive is FAT 32, the new one is NTFS. There is
> nothing wrong with the new hard drive according to WD:s
> disk check utility.
>
> Comments, please?
>
> Mikael