XP password demanded

A friend of mine reports that, after installing the latest
version of Avast! Free and restarting his computer, Windows
XP now demands a password at startup - where it didn’t
before. Meanwhile, he has no idea what the password could
be.
If we don’t find a way around this, he’s going to have to
reinstal windows and lose all his data. Does anyone know if
Restoring XP would solve the problem?
Without having checked the info he’s given me, it seems to
me advisable, after installing the latest version of Avast!
and before closing down or restarting, to check that no
change has taken place in Windows startup settings - user
accounts, auto login, use of passwords …
Avast! hasn’t done this to me but another program did
something similar under 2k - which required altering the
registry to restore things.
Unless someone has a bright idea, I plan to boot his
computer with a Bart’s PE cd and carry out the Privilege
Escalation Exploit - involving logon.scr and cmd.exe

uh… try http://www.pogostick.net/~pnh/ntpasswd/ (a lot easier than all that screen saver mess you found).

As for Avast making the computer “demand a password”, that’s BS.

He may be accusing avast because that’s the last thing that he remembers doing on his computer, but none of the installs that I’ve ever done has made this happen.


Nor have any of the install I have done made this happen.
If that were a fault of avast, we would be deluged with complaints.


Thanks for the suggestion. It’s better than the one I mentioned

  • which requires knowing the pw.
    It’s not necessarily Avast causing this, it’s more likely Windows.
    A quick search shows similar happenings are not all that rare.

No problem. I’ve used that program to either change passwords or remove them quite a few times. It works wonders.

Hopefully you find the real culprit of the password issue and get it resolved.

Good luck!

I am having the same problem. And I have seen this problem mentioned a few times through out the forum. Yesterday my dad paid for avast and after the computer the “log on to windows” screen pops up. Now I would assume this would be doing this because of avast. Because that was the last thing done on his computer. And he has windows xp just ad the other person. So my question is what is the password? And if I don’t have access to another computer to make a password cracking disc how else can I log in? My dad had never had a password on here at any time, so that is why this is pretty confusing.

I have this same problem and i’m shure it’s because avast instalation.

Open avast, go to the vault and you will find logonui.exe file, restore the file and windows will start normaly, but avast will block it again.

Also explorer.exe and many other system files are blocked, why?? after a while have the start in safe mode to unistal avast.

Can anyone help me please, many .exe files are being confused by viruses, had to instal windows for the 3rd time today.

P.S.- I apologize for any error how i write, don’t speak english very good.

I suggest:

  1. Clean your temporary files.
  2. Schedule a boot time scanning with avast with archive scanning turned on. If avast does not detect it, you can try DrWeb CureIT! instead.
  3. Use MBAM (or SUPERantispyware or even Spyware Terminator) to scan for spywares and trojans. If any infection is detected, it is better and safer to send the infected file(s) to quarantine (Chest), rather than simply deleting them.
  4. Test your machine with anti-rootkit applications. I suggest avast! antirootkit or Trend Micro RootkitBuster.
  5. Make a HijackThis log to post here or this analysis site. Or even submit the RunScanner log to to on-line analysis.
  6. Clean your Hosts file (replacing it) with HostsMan tool.
  7. Disable System Restore and then reenable it again.
  8. Immunize your system with SpywareBlaster.
  9. Check if you have insecure applications with Secunia Software Inspector.

Definitively, they don’t seem to be false positives of avast… Are you really reinstalling Windows? Is it legit?

Yes i’m realy installing windows, with a original cd and key, just did it again on a home edition, seconds after installing avast it started to alert about viruses and it does not stop until i disable it and unniistall avast.

already try on 3 computer and always the same problem, going to try a other antivirus to see what will hapend.

Can you submit the files to www.virustotal.com ?
It would be very helpful to check if they’re not false positives.

Tech
If you can’t get past the login how can you do all those things, or am I missing something ???

Maybe we’re talking about different users…
If avast is installed and warning the user, he/she did login.

Pacheco81

Could be an oldy
http://www.ozzu.com/mswindows-forum/help-deleted-logonui-exe-windows-welcome-screen-gone-t72987-15.html

Hi, thanks, it’s looks the same problem, but i don’t have only this file missing (moved to quarentine), many files are detecded as virus, ex:

logonui.exe C:\WINDOWS\system32
spoolsv.exe C:\WINDOWS\system32
iexplore.exe C:\Programas\Internet Explorer
wpabaln.exe C:\WINDOWS\system32

These only by starting windows and trying to open I.Explorer

If i scan the computer with avast it will find hundred’s of viruses (that i’m almost shure they not)

Did a full scan and found 1175 viruses on a pc that i just finish installing windows ???

Anyone else have the same problem??

Which is your virus definitions version?
Everything is so strange…

110120-0

Yes it’s very strange, diferent computers, try with diferente windows install cd, and always the same problem.

Update to the latest…

This is exactly what I am saying. I can’t get pass the login. So avast clearly set up a password, that I don’t know. I’m not about to reinstall xp back on my computer. I to many files that I haven’t backed up. Plus that doesnt seem to be a fix

Have you tried booting to safemode and selecting the Administrator account?
Often the password is null, just hit the enter key if prompted.