Windows 7 makes use of some more advanced security features to safeguard user files. This means that if you try to read or change files/folders that do not belong to you then you will get an error stating You don't currently have permission to access this folder. To gain access to these files you will need to "take ownership" of them using the following steps.
First, you will need to select the file or folders that you wish to take ownership of then right click them and select Properties:
Then select the Security tab and click Advanced:
Now select the Owner tab and click Edit:
Choose the new owner of the files, check the "replace owner on subcontainers and objects" and click OK:
You will be presented with a notice that you are granting full control to a new user - if you wish to do this, click Yes. Now OK all of the remaining property windows and you will now have control over the selected files/folders.