Creating a Default File Opener :-by Aman jain

If you have a un-registered file type and want to view it instead of having to select Open With. Use Explorer's Right-click and add your program to the right-click options by: 
1. Open RegEdit 
2. Go to HKEY_CLASSES_ROOT\Unknown\Shell 
3. Right click on "Shell" and create a New Key and name it "Open " 
4. Create a New Key under the "Open" key you just created and name it "Command" 
5. Set the (Default) value to the path and filename of the program you want to use to open the file type 
6. For example: C:\Windows\NOTEPAD.EXE %1 
You must use the "%1" for this to work.and a space between the exe and the %1

Creating a Logon Banner :- by Aman jain

If you want to create a  Logon Banner: A message box to appear below your logon on.

1.Open RegEdit
2.Go To
For Windows 9x and ME -
HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\ Windows\ CurrentVersion\ Winlogon

For Windows 2000 XP 2003 Vista - 
HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\ Windows\ CurrentVersion\ Winlogon

3.Create a new String value"LegalNoticeCaption "
4. Enter the Title of the window. What is displayed in the Title Bar.
5. Create a new string value "LegalNoticeText"
6. Enter the text for your message box that will appear even before the Logon window