Is it possible to restart Mac into OS X once switched over to Windows but logged out? Sorry if my question title seems confusing. I have a very specific situation here. My brother died and I have inherited his Mac. I don't know any of his passwords and can't access anything. His Mac itself is not password protected (I can use his computer) but to make any administrative changes/install programs/etc, I am prompted for a password. I don't know it, so I am unable to do anything admin-wise.

I recently tried switching over to the Windows HD side to see if there were documents or any important info he saved over there. However, the Windows side is password protected and I am unable to login.

So now, I am pretty much in a deadlock. When I restart the computer, it restarts in Windows of course. I am wondering if there is a way to restart into OS X with keyboard shortcuts or something? 

I tried loading in a pw reset disk to do the windows pw recovery, but for some reason the computer is not identifying the disk.

I am totally stuck.

My brother was an engineer/programmer/developer. I am trying my best without him to be the family's IT person now. 

I know he used this site a lot, so I figured if anyone could help, it's you guys. Thank you.
To boot back to OS X, press the option key and hold it down. You should get the choice to boot OS X, Windows or recovery.

Screw the disk out and put it on an usb-reader.
You don't need any password if the disk is not encrypted to obtain its data from it.