Upon logging into Windows 7, you may have noticed moments when the system lagged at the Welcome screen. It seems your choice of wallpaper could be the culprit.

Some users who opted for a solid color background found themselves waiting for up to 30 seconds. A recent blog post by Microsoft veteran Raymond Chen sheds light on the issue, attributing it to a programming glitch.

After authentication, Windows needs to gather various elements to initialize the desktop. Chen explains:

“The logon system waits for all these pieces to report readiness. If they don’t signal on time, the Welcome screen persists. This is likely the reason behind the frustrating 30-second delay.”

For those who opted to hide desktop icons, they might have experienced similar delays due to the OS searching for non-existent icons. Fortunately, this issue was resolved just five months after Windows 7’s launch.

Chen also shares insights about other programming oddities on his blog, known as Old New Thing.