
Solid color desktop causes 30-second delay in Windows 7 Startup Time - mcav
http://support.microsoft.com/kb/977346
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mmastrac
You can probably work backwards from the KB article to the underlying problem. 

This is listed as a workaround:

"Configure the value of the DelayedDesktopSwitchTimeout registry entry.  This
value determines the time-out interval of a session before Windows 7 or
Windows Server 2008 R2 switches between sessions." 

In Windows, the login screen and user desktops run in different window manager
sessions.  There's a similar KB article that explains this in a little more
detail:

<http://support.microsoft.com/kb/940452>

"This issue occurs because the logon process runs in session 0.  However, the
logon script process runs in a different session.  A 30-second delay occurs
before Windows Vista switches from session 0 to another session.  When the
logon script interacts with you before the logon script process is complete,
you have to wait for the 30-second time-out interval of session 0.  To fix this
problem, change the time-out interval to less than 30 seconds." 

The login scripts in Windows run before the user's desktop appears.  It seems
reasonable that there's a trigger sent from a process that runs after the
login script terminates that tells the OS to switch from session 0 to the new
user's session.  This is likely to prevent the desktop from flickering between
the different login states. 

In case there's a problem with logging in that wasn't expected, there's a
failsafe timer, defaulting to 30s (hence the 30s login delay in both KB
articles) that triggers the switch from session 0 regardless of the login
state. 

Given that, and the reference to stopping the "Desktop Window Manager Session
Manager" in the linked KB, I would imagine that the solid-color desktop
interferes with the login process by either crashing the service that renders
the background, therefore failing to send the appropriate trigger or triggers
a different code path that fails to send the signal. 

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rbanffy
I would love to know what causes this... I guess they'll never tell. 

~~~
tlack
Random idea: they might be using a single pixel "image" that they generate in
memory, and then handing that image to their tiling routine, which duplicates
and tiles it all over the massive resolutions we use today.  Back in the day,
using small tiling images on webpages was discouraged because slower
computers/browsers would take forever to render them, even though they were
simplistic in appearance. 

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jcl
According to the article, using a solid-colored image for the background is
actually a workaround for the problem. 

The fact that the symptom is a hard 30-second delay independent of processor
speed, resolution, or graphics card suggests that the computer is not actually
chugging through anything. 

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fhars
And they auto-translate the website to the language of the browser.  So if yo
happen to access the page with e.g. de_DE as preferred language, they sound
like _complete_ morons. 

~~~
rbanffy
Then I guess the original language isn't English either. 

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dbz
I wish I could comment on those pages. 

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Indyan
are there any other such interesting yet little known bugs in Windows 7? 

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st3fan
During those 30 seconds, China will steal your s3cr3ts.