Computer Centre, IIT Kanpur

Indian Institute of Technology Kanpur 


You start some 16 bit Windows application and get the following message:

C:\Windows\System32\AUTOEXEC.NT. The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate this application.


If you run into this problem, the cause is that one of the following files is missing from \WINNT\System32:

  • Config.nt
  • Autoexec.nt

Check to see that these files are there. If not, expand them from the install CD and copy them to \WINNT\System32.They'll be in the \I386 folder as:

  • Config.nt_
  • autoexec.nt_
  • command.co_

An example of expanding Config.nt_ is as follows:

expand config.nt_ config.nt


You get an error of "missing file" while opening your drive through My Computer.


This problem generally occurs when a file named "autorun.ini" is created by the virus with some malicious code written in it. The “autorun.ini” file is executed when the drive is double clicked with the mouse or by pressing enter on the drive. To resolve the problem:

Open command prompt and select the drive letter eg:- d:, and run the command "dir a*.* /a" to view the above stated file.

If the file exists there, then delete "d:\>del autorun.ini /a" and the restart the computer.

You can also turn off the "Autorun" feature of the Operating System

In Windows XP:

Open Run command, type "gpedit.msc" and hit Enter, then explore Computer Configuration => Administrative Templates => Systems and then click on right panel and open “Turn Off Autorun” => Enable => Select from drop down list "All Drives". Do same as in User Configuration.

In Windows 7:

Click on Start => Default Program => Change AutoPlay Settings => Remove Check Mark from "Use AutoPlay for all media and devices”.


  • Never double click the external drives (external HDD, Pen drive etc.) for opening.
  • Just explore them by right click menu.
  • This will protect from the execution of Autorun file code.


Antivirus reports Virus/Trojan found messages repeatedly.


Disable File and Printer Sharing.

File and printer sharing is an essential component of Microsoft Windows Networking which enables us to share our files, printers and other network resources. However, this service is also a cause of spread of Virus, worms and Trojans. Though most of the users normally do not use file and printer sharing, this service is enabled by default in Windows XP and Windows 7.

To disable File and Printer Sharing

Share your Shared folders in your networks, if it is necessary but it is not recommended for Home PC or Personal PC.

If you don’t want to share any files, folder and resources of your computer, then you can disable the file and printer sharing support from:

In Windows XP:

Go to Control panel => Network Connection => Right Click on “Local Area Connection” => Properties => Remove check mark from “File and Printer Sharing for Microsoft Networks” => Ok AndControl panel => Windows Firewall => Exceptions Tab => Remove checkmark from “File and Printer Sharing for Microsoft Networks” => Ok

In Windows 7:

Go to Control Panel => Network and Sharing => Change Adapter Settings => Right Click on “Local Area Connection”=> Properties => Remove check mark from “File and Printer Sharing for Microsoft Networks” => Ok And Control panel => Windows Firewall => Allow a program or feature through Windows Firewall => Remove check mark from “File and Printer Sharing for Microsoft Networks” => Ok