Whether the owner of the computer as a guest without the knowledge of the administrator's (Seller) password and username, has a right or not to downlad any thing?

Previously I have placed the content here.Where has it gone? Just now it was written with every explanation of the issue
I am the buyer of this computer.The seller of this is the administrator.He,without telling me his user name and password he left this place Only with guest provision it was under emergency sold to me.
The seller's (Administrator) arrival is not known.Phone contact even was not possible.Under these circumstances what is to be done may be advised.How to download? Is there any alternative?
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in reference to: Administrative privileges required : - Google Help (view on Google Sidewiki)