The Windows 10 April 2018 update to version 1803 has caused problems with the Windows File and Printer sharing and may have caused some PCs to enter a boot loop or boot to a black screen.  Other issues have been reported, with most of these have been resolved.  The Windows File and Printer sharing are currently ongoing.

ComputerWorld: Microsoft unexpectedly starts pushing Win10 version 1803 through Windows Update

ComputerWorldWin10 1803 bugs roll in: Chrome freezes, Skype burps, Alienware craters and… hey, Cortana? This was from a Microsoft MVP on their support site.  The solutions here may not work, but it can rule out some of the other problems:

At this time Microsoft has not released any updates or statements on the update.  Our support technicians are not able to resolve this issue as it is a Windows level issue.  Our support technicians can still contact the salon and determine root cause of the problem, but if the issue is caused by an update to version 1803 we will not be able to resolve it.

If your business cannot wait for an update from Microsoft, you can attempt a system restore to a point before the April update.  This may take several hours depending on the age of the restore point and the number of changes occurring.

WARNING: If the PC loses power during the system restore, the Windows operating system may become damaged.  You may want to consult your computer technician before performing a system restore.

Microsoft has information on performing a system restore located on their website:

Windows Users can defer updates in Windows 10 for a certain period of time:  Microsoft has information on how to defer the updates here Windows Professional users can pause the Windows updates for a set duration: