Slow logon with a blank screen in Windows

This article provides a workaround for an issue that makes Windows logon slow, with a blank screen displayed during the delay.

Applies to:   Windows 10 - all editions
Original KB number:   3161390

Summary

Remote Desktop and console users experience a slow logon with a blank screen before the desktop is rendered in Windows. Longer logon times directly correspond to the number of desktop shortcuts that are defined in the user's profile.

Symptoms

In this situation, you might notice that the logon times increase continually. A blank screen may be displayed during this delay period. You may also notice that Explorer.exe consumes excessive CPU resources.

Additionally, Procmon shows that affected computers are busy accessing the following registry key:
HKEY_USERS\S-1-5-21-xxxxxxx\Software\Microsoft\Windows\CurrentVersion\UFH\SHC (or HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\UFH\SHC)

You may also notice frequent changes or additions to shortcuts on the desktop. This might occur if you use a logon script to update the desktop or in a Remote Desktop situation in which the cached profile is deleted. This makes all entries new on the next logon.

Workaround

To work around this issue, configure a logon script to delete the following registry key during logon: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\UFH\SHC

You can also use Group Policy preferences to work around this issue.

Note

There's a known issue when you use this workaround. As soon as the script is in place, users will see entries on the Start menu marked as "new" even though there aren't any newly installed applications or items. It might be a good idea to share this information with users to prevent them from logging a call with the Service Desk about this.