Windows 2000/2003 Security

Hi, I have installed a windows 2000 server sp4 with all updates,  it's a member server. I can't copy files to eg c:\windows\system32; but can create new files ?! I can't stop some services eg Mcafee services. ...

I have loose my product key, I'm \running a Window XP professionnal and wanted to download internet exploer 7. Whithout the key I am in trouble what to do? Thanks. ...

I'd like to create a group in 2000/XP that basically mirrors the Guests group.  Ideally I'd like to copy the Guests group directly, but assuming that's not doable... How do you determine the permissions that are assigned to the Guests ...

Does anyone know what the difference is between these 3 security templates that come with Windows 2000: basicwk.inf (or basicsv.inf) defltwk.inf (or defltsv.inf) setup security.inf I've seen a few sites that say basicwk.inf (or basicsv.inf) contains ...