Home network woes

I am trying to set up a home network within Windows 7 so it can communicate with two other machines, one has installed XP, the other Vista.

I have set up home networks in the past no problem (not on 7) & whilst I can get all 3 PC's talking to one another it appears that XP & Vista can not only see my shared documents but also my user documents, more worrying is that both other machines can edit or change any of my user documents!

I would prefer none of the other PC's connected to the network to see my documents let alone gain access to them & whilst this folder is supposedly locked it isn't!

I would be greatful for any help, thanks.

Images for reference of my PC:

It appears you have an additional setting in Public folder sharing than me!

passwords on all machines and accounts setup? This is a must

I sorted my problem.

I turned off network discovery in home or work.

I enabled network discovery for public (password protected of course).

Now the other computers only have access to my public folder and not my private documents.