The simplest solution is not Firefox specific.

You set up separate User Accounts on the computer. It is probably best to use Ordinary or Limited Accounts, as opposed to Administrator accounts.

Firefox will be installed globally but each user will have their own Windows computer Account, and the user will have their own Firefox profiles with their own bookmarks and logins etc.

See

• Types of user accounts (Actually a Windows XP article.) https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/ua_c_account_types.mspx?mfr=true
• Set up accounts http://windows.microsoft.com/en-us/windows-10/getstarted-set-up-accounts

Note that this is not about a bookmark, but about the the name and password that is stored in the Password Manager. Firefox can store multiple names and passwords for a website and you can select one from a drop-down list, but in such a case everyone that use the computer and this profile can have access.

• https://support.mozilla.org/kb/use-master-password-protect-stored-logins

For more privacy it is at least recommended to use separate (multiple) Firefox profile folders if you do not want to use separate Windows user accounts. You can use the Password Manager to create additional profiles.

You can create a desktop shortcut to start Firefox with a specific profile by adding a space and -P "profile_name" to the target field in the properties of the shortcut.

See:

• https://support.mozilla.org/kb/Managing+profiles
• http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_windows
• http://kb.mozillazine.org/Shortcut_to_a_specific_profile
• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox

See also:

• https://developer.mozilla.org/Mozilla/Multiple_Firefox_Profiles
• https://developer.mozilla.org/Command_Line_Options