The problem is that in WIN 7 (and other WINs for PC use) you can protect a file with a password, but NOT a folder.
There are numerous workarounds :
1. Make a BAT file in said folder : link
2. Forbid to certain people access to said folder : link
3. Encrypt the content : link
4. Compress the data with a password. This is not usable for data that is often in use, of often changed (7 zip is good for this).
But all of this is not exactly elegant, and not really a solution.
To protect a folder under WIN 7 from anybody, you need 3rd party software – a list of options (one of them) may be found here.
People who have tested such SW say that more than one should not be used/installed on a PC, since they can get into conflicts.
Programs I have taken a look into :
1. Folder lock – commercial (link)
2. Folder guard – commercial (link)
3. Lock-a-folder – free, and has the most downloads off all that I have seen suggested (link), the problem is that it is very old (last version is from 2012)
4. Easy file locker – it does not say that it is free, last update is from 2016, problem is it has VERY bad comments, so I am not even going to try it!
4. 4 in 1 folder locker – not explicitly free, last update is from 2015
5. Microsoft private folder – free, but ooollldddd (2006), and works only on WIN XP
6. Protect folder – free, but only up till 20th opening, so not for me!