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Top Document: Children's Software FAQ Previous Document: 4. Resources Next Document: 6. Pointing Devices (this topic is not well-covered in the rough draft) See reader questions & answers on this topic! - Help others by sharing your knowledge A problem that concerns many people when they start letting their children use their computers is how to keep the children from destroying important files or otherwise wreaking havok on their computer. Here are some solutions suggested by people on misc.kids.computers. Suggestions for MS-DOS/Windows were compiled by Stephen C. Steele, and a more recent copy might be found at http://qv3pluto.LeidenUniv.nl/steve/reviews/protfile.htm. Protecting Files under MS-DOS/Windows Protecting files under MS-DOS and Windows systems is difficult: both Windows and MS-DOS are single user systems that assume a single user who should be permitted full access to all the resources of the computer. * Making Backups * Marking Files Read Only * Program Manager Restrictions * Replacement Shell Programs Note: this is a first draft of this document. Comments, further suggestions, and additional information will be gladly received. Stephen C. Steel reviews@qv3pluto.LeidenUniv.nl Making Backups This is the only absolutely reliable method to protect your data. Software can only do so much: it can't guard against a disk crash caused by someone flicking the power switch on and off too rapidly, bumping violently against the computer, etc. Besides, it will also save your data from your own mistakes, lightening strikes on the power line, etc.. If the files are really important, especially if you use them to earn your living, then back them up. It isn't usually necessary to rush out and purchase a tape drive which can back up your entire hard disk: you can always reinstall your application software from the original media, so you just need to backup the files you create with it. The storage requirements for this are usually much more modest: you may find that a couple of floppies a month is enough. This is easier to do if you keep the files you create separately from the application software and its example files. For example, I keep all my data files in subdirectories of C:\USER\STEVE. If you configure your Windows application icons with the appropriate default working directory (using the File|Properties command of Program Manager), this will be more or less automatic. Don't forget to make backups of important configuration files too: CONFIG.SYS, AUTOEXEC.BAT and all those .INI files in the \WINDOWS directory. Marking Files Read Only The read only attribute bit is an underexploited feature of MS-DOS that can be quite effective at preventing children from damaging important data. If you then limit access to programs that are capable of removing the read only attribute, such as the MS-DOS command ATTRIB.EXE and the Windows FileManager, the data in these files will be relatively safe: normal programs will not be able to delete or overwrite the protected data. There are two main difficulties with marking files read only. The first is remembering to mark all your work in progress files read only when you're finished working on them and then back to normal when you're ready to work again. This can be quite tedious if done manually, although it is much easier if all your data files are in one common directory tree. Then the MS-DOS commands cd directory attrib +R /s *.* can be used to mark an entire directory tree read only (or normal if +R is changed to -R). The second difficulty is figuring out which files can be marked read only without causing problems: most applications need write access to some files, and they may crash if this isn't enabled. Some DOS programs even expect write access to their EXE files in order to store configuration information. The information in files which can't be marked read only can be protected by making a read only copy with a different name or in another directory. Program Manager Restrictions There is an optional section to the program manager .INI file that allows you to restrict its capabilities. These options do not appear in any of the Program Manager menus; they must be added by editing the file PROGMAN.INI with an ASCII editor (such as NOTEPAD.EXE). The section must be named [restrictions] and the possible entries are : NoRun If you include the option NoRun=1, then the File|Run menu entry is disabled, and it is only possible to run programs from Program Manager if there is an icon defined in a program group. The NoRun option is only effective if none of the programs with icons defined can themselves be used to start additional programs (such as File Manager, for example). NoClose Setting NoClose=1 will make it impossible to exit the Program Manager, and hence Windows, with the File menu, control menu or ALT+F4. NoSaveSettings If NoSaveSettings=1, then any changes made to the arrangement of icons and group windows will not be saved when the Program Manager exits (regardless of how the Save Settings on Exit menu item is set). NoFileMenu Setting NoFileMenu=1 will disable the entire File menu of the program manager. EditLevel Setting EditLevel=n sets the following restrictions on modifying Program Manager settings: o EditLevel=0 allows user to make any changes (the default). o EditLevel=1 prevents the user from creating, deleting or renaming program groups. o EditLevel=2 sets all the restrictions of EditLevel=1, and in addition, prevents the user from creating or deleting program items. o EditLevel=3 sets all the restrictions of EditLevel=2, and in addition, prevents the user from changing the command lines for program items. o EditLevel=4 sets all the restrictions of EditLevel=3, and in addition, prevents the user from changing any program item properties (although they can still be viewed). Replacement Shell Programs There are a number of these on the market, such as Edmark's KidDesk Family Edition for Windows. These programs allow you to limit the applications individual users can run. The various users' access can be password protected. They have two main weaknesses: 1. They can be bypassed. Booting a computer with MS-DOS 5 or later with the left shift key held down will cause it to start up in a simple DOS session, ignoring the contents of the CONFIG.SYS and AUTOEXEC.BAT files. 2. If you allow your children access to any program which writes some sort of data to any filename they specify, then they can overwrite your important data files: "Hey Dad, how do you like my new drawing, I called it REPORT.DOC". Although they are not ironclad, the use of a program shell in combination with marking important files read only can be quite effective (since your children are less likely to need a program that can change file attributes than one that overwrite files). May 5, 1995 Stephen C. Steel reviews@qv3pluto.LeidenUniv.nl User Contributions:Top Document: Children's Software FAQ Previous Document: 4. Resources Next Document: 6. Pointing Devices (this topic is not well-covered in the rough draft) Single Page [ Usenet FAQs | Web FAQs | Documents | RFC Index ] Send corrections/additions to the FAQ Maintainer: gibbsm@ll.mit.edu
Last Update March 27 2014 @ 02:11 PM
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