To enable Task Manager, copy following code,paste it in any notepad and save as”EnableTaskManager.reg” file.

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesSystem]
"DisableTaskMgr"=dword:0000000

Double click it and your Task Manager will be restored.

Method:1

• Type gpedit.msc in RUN dialog box.
• Group Policy Window will be opened.
• Goto : User Configuration -> Administrative Templates -> System
• in right-side pane, set “Prevent access to Registry editing tools” to either Not Configured or Disabled.

Method:2

• Press Windows Key +’R’
• Type the following and hit Enter

REG add HKCUSoftwareMicrosoftWindowsCurrentVersionPoliciesSystem /v DisableRegistryTools /t REG_DWORD /d 0 /f

Method:3

Alternatively, Copy the following code,paste in any notepad and save as “EnableRegEdit.inf”

   [Version]
Signature="$Chicago$"  
Provider=Symantec  
[DefaultInstall]
AddReg=UnhookRegKey  
[UnhookRegKey]
HKLM, SoftwareCLASSESbatfileshellopencommand,,,"""%1"" %*"  
HKLM, SoftwareCLASSEScomfileshellopencommand,,,"""%1"" %*"  
HKLM, SoftwareCLASSESexefileshellopencommand,,,"""%1"" %*"  
HKLM, SoftwareCLASSESpiffileshellopencommand,,,"""%1"" %*"  
HKLM, SoftwareCLASSESregfileshellopencommand,,,"regedit.exe ""%1"""  
HKLM, SoftwareCLASSESscrfileshellopencommand,,,"""%1"" %*"  
HKCU, SoftwareMicrosoftWindowsCurrentVersionPoliciesSystem,DisableRegistryTools,0x00000020,0  

Right click it and choose ‘Install’ to solve the problem.

Today, I will introduce the basic network communication program using Transport Layer Protocol named TCP. This is really easy to implement in JAVA. There are two files in this program. A client program and server program. It is important to note that the server program must be started first at the server and then afterwards, run the client program.

tcpserver.java

import java.io.*;  
import java.net.*;  
class tcpserver  
{
    public static void main(String args[])throws Exception
    {
        System.out.println("Server started....n");
        try
        {
            ServerSocket welcome_socket=new ServerSocket(1234);
            while(true)
            {
                Socket listen_socket=welcome_socket.accept();
                BufferedReader server_input=new BufferedReader(new InputStreamReader(System.in));
                BufferedReader client_out=new BufferedReader(new InputStreamReader(listen_socket.getInputStream()));
                DataOutputStream server_out=new DataOutputStream(listen_socket.getOutputStream());
                String client_str,server_str;
                client_str=client_out.readLine();
                System.out.println("Client:"+client_str+'n');
                System.out.println("Enter message:");
                server_str=server_input.readLine();
                server_out.writeBytes(server_str+'n');
            }
        }
        catch (Exception e)
        {
            System.out.println("Error:"+e.getMessage());
        }
    }
}

tcpclient.java

import java.io.*;  
import java.net.*;  
class tcpclient  
{
    public static void main(String args[])throws Exception
    {
        System.out.println("Client started...");
        try
        {
            Socket client_socket=new Socket("localhost",1234);
            while(true)
            {
                BufferedReader client_input=new BufferedReader(new InputStreamReader(System.in));
                BufferedReader server_out=new BufferedReader(new InputStreamReader(client_socket.getInputStream()));
                DataOutputStream client_out=new DataOutputStream(client_socket.getOutputStream());
                String client_str,server_str;
                System.out.println("Enter message:");
                client_str=client_input.readLine();
                client_out.writeBytes(client_str+'n');
                server_str=server_out.readLine();
                System.out.println("Server:"+server_str+'n');
            }
        }
        catch(Exception e)
        {
            System.out.println("Error:"+e.getMessage());
        }
    }
}

Method:1

• Type “regedit” in run command and hit ENTER. A window named REGISTRY EDITOR opens up.
• Find any of the following keys:

User Key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

System Key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

• Find the VALUE with Value Name as NoFolderOptions, Data Type as REG_DWORD (DWORD Value) and Value Data either as 0 = show options or 1 = hide options. If you see these values, then you can delete it safely.

Method:2

• Press Windows Key +R
• Type gpedit.msc and hit enter
• The ‘Group Policy’ dialog box will appear.
• Navigate to ‘User Configuration’>’Administrative Templates’>’Windows Components’>’Windows Explorer’ Goto Tools>Remove Folder Options>Right Click>Properties>Disable>Apply

Method:3

To enable Folder Options, copy following code,paste it in notepad and save as “folderoptions.reg” file.

Windows Registry Editor Version 5.00  
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
"NoFolderOptions"=dword:0000000
[HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Restrictions]
"NoBrowserOptions"=dword:00000000

Double click it and your folder options will be restored.

Today, I want to share about creating a light sensing robot which follows the path of light. I used discrete electronics rather than programming micro controllers. But this works. Cool huh? I have embedded a video to show it’s working.

All you need to create this robot:

A PCB
Two LDR’s
Two 330 ohm resistors
Two NPN Transistors(ST2N 2222A G4 C)
5k ohm pot( potentiometer)
2 toy motors
12 volt DC supply,
connecting wires and soldering equipments.

The circuit diagram is shown below. If you have any doubts fabricating this circuit, feel free to contact me.

The logic behind this is simple;

“If a LDR senses light, the motor connected to it must stop and the other Motor should rotate. Then Only it will go to the direction of light.”