Please help - location is not available - access is denied

Hey People,

system specs
Windows Vista Ultimate, 64 bit, SP2

I was playing around with the permissions for one of my secondary drives that holds data e.g videos, mp3s so that my pal couldnt get into them and mess around with it and know it gives me this message everytime i try and access the drive.

Location is not available (this appears in the title bar of the error message)
I: is not accessible (this appears in the main part of the error message)
Access is denied (this appears under the above message in the error message)
And there is only an OK button i can press.

So here is how this all came about.
I right clicked on the drive,
selected properties,
Clicked on the security tab,
clicked on the "users" option under the "Group or user names" section,
Clicked on "edit",
clicked on the "users" option under the "Group or user names" section,
selected "deny" for every box under the "permissions for users" section,
clicked apply,
an clicked "ok" until the windows were all closed.

The drive name was then changed to "Access Denied" after i had done this with no letter assigned to the drive.
I went into computer management and assigned a drive letter but still no good.
I now right click the drive and select properties and the security tab is no longer there, so i cannot reverse the permissions.
I am logged in as an administrator.
I have tried to turn off UAC with no luck.
I have attempted to create another administrator account and change the permissions from there but no good.

So does anyone out there know of how i can get this drive accessible so i can access my files???

Thanks for tuning in guys,
Your help or assistance is greatly appreciated.

Cheers from Australia!