Event ID - 64021

Event Id64021
SourceWindows File Protection
DescriptionThe system file <drive:\path\filename> could not be copied into the DLL cache. The specific error code is 0x00000000 [The operation completed successfully.]. This file is necessary to maintain system stability.
Event InformationDifferent causes and and its solutions can found from following links to Microsoft documents.
Reference Links Installation of HP 2000c Printer Causes Event ID 64021 for Windows File Protection

Windows File Protection Logs an Event ID: 64021 When You Run the SFC Utility

Windows File Protection Event ID 64021 When You Install Hotfix

Service Pack 1 Installation Generates Windows File Protection Event Log Entry

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.