Windows XP Fix for DNS Vulnerability possibly breaks XP Logon Screen


The dorty hakkaz have spotted something so Microsoft et al have had to roll out a fix.  Specifically, it’s a DNS hack that allows the bad guys to spoof code, pages and even complete websites!  Here are some bits of info today:


The trouble is either the DNS fix or one of the three others in the Patch Tuesday for July made the Windows XP logon screen only work for one logon instance – the first one.  After that, typing into the password boxes did nothing and the only way to log on was to Ctrl+Alt+Del twice to get the old Windows NT/2000 user logon screen prompt.  This is the same problem from earlier in the year that someone else had:

This is what I did…

(after each step I did a full reboot and two sequential logons for each step. )

System Restore – no joy

Re-installed updates – no joy

Did google search and tried the gpedit.msc and following suggestions – no joy, security template gone message

Disabled Fast User Switching – no joy

Disabled Welcome Screen – WAHAY!  All working.

Extra Information

This happened to both my Windows XP SP3 machines today after updating from the windows update website.  hmmmm 😕


So my solution to a non-working Windows XP logon screen is to disable Fast User Switching and the windows welcome screen with all the users on it.  Basically to just have the old w2k logon screen.

Afterwards I checked that the gpedit.msc security template was back up and running.  It was, so I did the above again to see if the XP logon screen and/or fast user switching would trip back into action – but they didn’t.

The same behaviour happened on the other PC so it’s something in the updates that doesn’t roll back on system restore, or else it’s been manifest for a while without me or anyone else noticing…

The PC’s are marginally snappier without fast user switching and the time to work after logon is a bit quicker too, as one would expect.

I don’t know why this behaviour has started but life’s too short for an in-depth play at the moment.  Microsoft say that there could be multiple instances of Comctl32.dll as one answer….It’s not a new problem.  This Microsoft Knowledge Base article is from 2007.

But it’s a long list.


By Strangely

Founding member of the gifted & talented band, "The Crawling Chaos" from the North-East of England.

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