How to restore a moved common folder to default location?

I've 2 logical drives with D: meant for for data. C: was running out of
space, so I moved all the Common Folders (Documents, Pictures, Videos, Links
etc) onto D: drive (eg D:\Documents)...but accidentally for Downloads it was
direct in D:\ root.

So when I open my personal folder, for Downloads it is replaced with the D:
drive icon (replaced the usual green/blue Downloads folder icon) consisting
of every data folders plus the recently moved Common Folders. So messy.

I wanted to restore the Downloads common folder back to default
"C:\Users\Steve\Downloads" but Vista won't let me with an error message:
Failed to build the list of regular subfolders under "D:\System Volume
Information" Access is denied.

It's driving me nuts, no one including MS tech support can help. I need an
easy solution, can you help me please?

--
Steve