Try using the Homegroup. Also, to map drives make sure you have the username and password correct. I know you probably know this but you need the username and password of the pc you are trying to connect to. I have also seen many times people change their user profile name via the control panel, if this has been changed you need to original user profile name that Windows sees. For example they buy a pc and the user profile is named Owner, they go to the control panel and change it to "Tom" their name, when you try and network this pc you don't use Tom for the username, you have to use Owner. Go to C:\Users and make sure you are using the correct username.