OK...a few words of explanation
The logon screen appeared on your system, just as it did on mine (months ago)...because you installed a version of MS.NET Framework
. It's one of those features of MS.NET that users were not properly warned about but which happens automatically.
Rather than explain what it was intended to do...just accept the fact that it was created by installing some version of MS.NET (which is necessary for many systems) and it is a benign item.
The login screen that appeared because of this...can be overcome, if it's a nuisance. The login screen is intended to be a security feature of MS.NET, but some of us interpret it merely as a nuisance (because we don't use login/password to access our systems).
Not sure what you did before...but all that you did may have corrupted some files. Please don't follow that route any more. I suggest that you run the chkdsk /r command on your system partition...the next time you boot into XP.
Re welcome screen, see http://www.computerhope.com/issues/ch000537.htm
If you absolutely feel that you must...you can even delete the ASP.NET account. See pertinent comments at http://www.daniweb.com/forums/thread14059.html
Edited by hamluis, 24 June 2010 - 09:40 AM.