Sometimes people say they are "stuck" because they don't know where they need to snoop - not always because they can't open a door ...
If you don't know where to snoop ...
YouTube is your friend.
These are old quests -- searching the web for videos using the following words
It's either the first or second video listed in the results
If you can't open the door - use the bugfix iury mentions.
If you have to ask - don't mess with it because you'll could seriously cause severe problems with your computer.