Windows 7 - cannot access d drive after installation

Here is the story. I was running windows 7 ultimate 32 bit version. I decided to install the 64 bit version so i formated my c drive and installed the 64 bit version. All well and good except now i cannot access my d drive. I get a message "access denied".
When i was using the 32 bit version i had my d drive permissions set up so that only I, as the administrator could access it and the kids login couldnt.
I have gone into its properties and made myself the owner but still cannot access it. Also i notice that when looking at the properties it says that the drive it no free space left on it when it actually has about 300 GB left.

I have been told that the problem is something to do with the permissions being placed on the drive while in 32 bit windows and now i am trying to change it in 64 bit windows. Any solutions to fix this??

thanks

David