To protect or not to protect?

When deciding which folders you want Folder Guard to protect, consider the following issues:

The folder in which Windows is installed (usually C:\Windows) must NOT be restricted with the No access or Hidden protection attributes. The same applies also to the folders where the user profiles are stored (usually it is C:\Documents and Settings or C:\Windows\Profiles). As a matter of fact, Windows needs to be able to write data into the files located in such folders to operate properly; if you restrict access to such folders, it may cause Windows to display error messages or even fail to boot. Make sure you know how to reboot Windows in the "safe mode" before trying to protect such folders! Also, see below for some hints on how to protect such folders.
Most subfolders of the folders C:\Windows and C:\Documents and Settings must have their access attribute set no stronger than Read-only. You can try assigning the No access and/or Hidden attributes to such folders, but first make sure you have backed up your system and know how to use the "safe mode" of Windows.
Many Windows applications on your computer are installed into subfolders of the C:\Program Files folder. If you hide or restrict access to this folder or its subfolders, the applications installed there may become inaccessible.
If you assign the Empty attribute alone to a folder, it does not make the folder inaccessible. The contents of such a folder will be invisible for Explorer, but the user will still be able to access files in the folder by other means, such as shortcuts. To make the contents of a folder inaccessible, use the no access attribute as well.

Protecting the C:\Windows and C:\Documents and Settings folders

Special care must be exercised when protecting these folders. DO NOT apply the no access or hidden attributes to them, because this will prevent Windows from working! (Windows is just designed so that these folders must be accessible and visible, at least partially).

If you need to restrict other users from tampering with files located in these folders, then, first of all, backup your entire hard drive, if you have not done so before installing Folder Guard. It will save you hours of your time if anything goes wrong (and believe us, there are things that may go wrong when you are trying to protect these folders).

You may try to make the C:\Windows folder read-only, however keep in mind that Windows and some other programs need to be able to write information into the files kept in this folder in order to operate properly. You may need to set up filters to allow other programs full access to their configuration files in the C:\Windows folder.

In addition, Windows uses some of the subfolders of the C:\Windows and C:\Documents and Settings folders to store its data, so you will need to mark such subfolders with the full access attribute. Examples of such subfolders are: Spool, Application Data, Cookies, Downloaded Program Files, History, msdownld.tmp, TASKS, TEMP, Temporary Internet Files, and others, depending on your configuration of Windows.

You may try to restrict the visibility of the contents of the C:\Windows folder by marking it Empty with Folder Guard. This may or may not work well for you, depending on Windows components and other software installed on your machine, so you will need to test your protection configuration well.

When restricting the visibility of the Windows folder, keep in mind the following:

Some subfolders of the Windows folder that are used by Windows itself (System, System32, Fonts, Profiles, Temp, etc.) must remain visible. You may try to mark some of them as read-only, though, but whether it works depends on other settings of Windows.
If you mark the C:\Windows folder with the Empty attribute, you may not be able to access the programs kept in this folder (including Explorer.exe, Notepad.exe, etc.). You should review the contents of this folder with Explorer before restricting it, and move the files that you want to be used into some other folder. If you do so, you may need to update the shortcuts pointing to those files, too.
If you restrict the C:\Windows folder for the default user, and Windows fails to work, you may try to restrict this folder for the non-default users instead.