Two Questions Vista Password and Open MG

Factual Questions
1

I looked through the computer section and did a search. Sorry if I missed these answers.

  1. We just got a computer returned at the store that a lady had put a password in. Can I get past her password and reformat? It’s windows Vista.

  2. On my home computer I’ve been downloading Youtube vids. The problem is when I go to the download folder to convert a file I frequently get an automatic OpenMG install screen which is a royal pain to get past. Eventually I can locate the file causing the problem but it’s way to time consuming to keep doing.

Should I worry about an OpenMG install or just do the install to avoid the issue? Or, can I prevent the auto install from popping up?