https://github.com/davepinch/pinchy.cc/blob/master/content/topics/computers/operating-systems/windows-7/windows-7.md
Why did Windows 7, for a few months, log on slower if you have a solid color background? (devblogs.microsoft.com) Imagine my surprise when someone pointed me to a support article titled “The Welcome screen may be displayed for 30 seconds during the logon process after you set a solid color as the desktop background in Windows 7 or in Windows Server 2008 R2.” Why is logon slower with a solid background?