If you did not give them your Windows discs, then they would not have been able to install it.
If you did it yourself you have not used up your licence. You can install Windows many times over with the same key. This particular machine is on its fourth.
As for the pdf, I assume you mean just the reader. It looks as though you have downloaded the full Adobe Acrobat. Just download the reader from the Adobe site, it's free. click here