Windows 7: Windows 7 Hard Drive Permissions

Hey guys , I'm not sure if this is a common issue or not but I'll having hard drive permission problems. Its basically my D drive that worked perfectly before but as of now , I cant write any data to it. From what I've seem , it should be resolved by going to Properties , clicking on the Security Tab , clicking on the User and going to Edit. You see , the problem is when I try to edit permissions, everything is grayed out. I can't do anything but click OK , Cancel or X out. Yes , I am also the main and only account in this system and again , had no issues up until recently.

Any idea?
Thanks in advance.

When you go to edit, you should be able to highlight a froup at the top box such as administrators then be able to edit their permissions in the lower box.

See if this helps, Permissions - Allow or Deny Users and Groups

I would try the above first, since it is your D drive you can try this Take Ownership Shortcut You may still have to edit permissions afterward.