The easiest way to block websites on your home computer is through the hosts file or you may also use OpenDNS for blocking adult sites.

However, when you wish to block time-wasting sites only for a temporary period, this VB Script should help. Run it once to block the site and run it again to unblock them.

    0:  
    1: 'Add the list of time wasting websites here
    2: WebsitesToBlock = Array("twitter.com", "www.youtube.com", "www.facebook.com")
    3:  
    4:  
    5: '-------------------------------------------------------------------
    6: ' LetMeWork.vbs - Block Time Wasting Websites
    7: ' Author: Amit Agarwal http://www.labnol.org/
    8: ' This script will block /unblock time wasting sites with a click.
    9: ' Internally, it will edit the Windows hosts file on your computer.
   10: ' For suggestions, send me an email at amit@labnol.org
   11: '-------------------------------------------------------------------
   12: '-------------------------------------------------------------------
   13:  
   14: If WScript.Arguments.length =0 Then
   15:  Set objShell = CreateObject("Shell.Application")
   16:     objShell.ShellExecute "wscript.exe", Chr(34) & WScript.ScriptFullName & Chr(34) & " RunAsAdministrator", "", "runas", 1
   17: Else
   18:  Const ForReading = 1, ForWriting = 2
   19:     
   20:  Set shell = CreateObject("WScript.Shell")    
   21:     root = shell.ExpandEnvironmentStrings("%systemroot%")     
   22:     hostFile = root & "\system32\drivers\etc\hosts"
   23:     tempFile = hostFile & ".bak"
   24:     
   25:     blocked = 0
   26:     towrite = false
   27:     
   28:  Set fso = CreateObject("Scripting.FileSystemObject")
   29:  Set f1 = fso.OpenTextFile(hostFile, ForReading, True)
   30:  Set f2 = fso.OpenTextFile(tempFile, ForWriting, True)
   31:     
   32:  Do Until f1.AtEndOfStream
   33:     
   34:         line = f1.Readline
   35:         towrite = true
   36:     
   37:      For Each URL in WebsitesToBlock
   38:          If instr(line, URL) Then
   39:              If blocked = 0 Then 
   40:                  If left(line, 1) = "#" Then blocked = 1 Else blocked = 2
   41:              End If
   42:             towrite = false
   43:          End If
   44:      Next    
   45:         
   46:      If towrite Then f2.WriteLine line
   47:  Loop
   48:     
   49:  For Each URL in WebsitesToBlock
   50:      If blocked <> 2 Then
   51:             f2.WriteLine "127.0.0.1" & vbTab & vbTab & URL 
   52:      End If
   53:  Next
   54:     
   55:     fso.Copyfile tempFile, hostFile
   56:     
   57:     f1.Close
   58:     f2.Close
   59:     
   60:  If blocked = 2 Then 
   61:         WScript.echo "Time wasting websites have now been unblocked!" 
   62:  Else
   63:         WScript.echo "Time wasting websites are now blocked!" 
   64:  End If
   65:  
   66: End If
   67:  
   68: ' By Amit Agarwal http://www.labnol.org/
   69: