i need to develop my own application with user name and password which allow users to login to windows.....how can i do tha....pl guide me on this......

thanks

Welcome asw.asela,

Of course we will guide you. Please show your efforts first. Read this Announcement - How to use bb code tags and Homework rules

Also I posted a code sinppet and answered a similar question earlier today. If you mean log in to your application (not windows) then see the posts:

Please see the thread:
http://www.daniweb.com/forums/thread200922.html

or code snippet:
http://www.daniweb.com/code/snippet1244.html

If you're trying to rewrite the windows login screen then I cannot help you. I'm sure it can be done but I wouldn't even know where to begin.

that correct....i need to do is windows logon application to replace my original. i know once i told this people think this is kind of a virus. no that's totally false. really im doing is winlogon application with qr barcode. i have developed a QR barcode decoder. my decoder works with a webcam. by webcam take a picture of the barcode and after few image processes and decode show the string of the barcode. so now im trying to do is pass that sting as the windows password and the user logon name will take from system automatically. once user show the barcode and click logon system need to match the string with win password and logon.....

that what im want to do.....i got my decoder and string i have no idea about how winlogon working and connect with c#.....

if need to show my decoder codes as my effert it doesn't matter i can show it any time to any one.......open source.......

i need every body help on this winlogon part......

please help me......