You'll need to reset the NTFS access permissions to access your old data. To do this, right click on the folders in your old drive and choose properties. Click the 'security' tab and click 'advanced'. In the dialog that pops up, under 'Permissions', remove all entries. Click OK twice to exit the properties box. Now, again open the properties and click 'advanced' (as we did before). This time, in the advanced box, click the 'owner' tab, and select "Administrators" as the owner. Click OK to exit the properties box. Again open the properties box, and click on security>advanced. Under the 'Permissions' tab, click 'add' In the "Select User or Group" dialog that pops up, type "Everyone" and click OK. In the next dialog that pops up, Check the box under "Allow" next to "Full Control" and also check the box at the bottom ("Apply these permissions to objects and/or containers within this container only") and click OK. In the next dialog, also check the box "Replace permission entries on all child objects with entries shown here that apply to child objects", and click OK. Once Windows applies the permissions, you should be able to access your files.
Hope this helps. Let me know if you still have problems.
Cheers.