Hard Drive / Windows 7 Permissions help

[Edinburgh Black Cat]

I am trying to wipe a hard drive but I am having trouble due to administrator rights.

I don't have the hard drive at hand at the moment but I'll give as much detail as I can remember.

The hard drive was removed from a broken laptop and is now in a SATA caddy thing.

I have copied everything on to my new laptop and now want to wipe everything so I can use it as a normal portable drive.

However, I am getting administrator permissions errors when trying to delete some folders (Users and I think Program Files and something else).

I think the way to resolve this is changing the administrator settings but my 'User' appears to be an administrator and I've tried to change the folder settings but have had little success.

Any suggestions?

Also I will probably want to delete some of this off my new laptop as well because I never checked what I needed before I copied it