Should I block it?

No, this file is 100% safe to run.

VersionsAdditional versions

6.3.9600.16384 (winblue_rtm.130821-1623) 3.33%
6.3.9600.16384 (winblue_rtm.130821-1623) 0.19%
6.3.9431.0 (winmain_bluemp.130615-1214) 0.09%
6.3.9431.0 (winmain_bluemp.130615-1214) 0.09%
6.2.9200.16384 (win8_rtm.120725-1247) 1.11%
6.2.9200.16384 (win8_rtm.120725-1247) 1.94%
6.2.9200.16384 (win8_rtm.120725-1247) 11.02%
6.2.9200.16384 (win8_rtm.120725-1247) 0.65%
6.2.8400.0 (winmain_win8rc.120518-1423) 0.09%
6.2.8102.0 (winmain_win8m3.110823-1455) 0.09%
6.1.7600.16385 (win7_rtm.090713-1255) 35.93%
6.1.7600.16385 (win7_rtm.090713-1255) 30.93%
6.1.7600.16385 (win7_rtm.090713-1255) 0.28%
6.0.6000.16386 (vista_rtm.061101-2205) 1.57%
6.0.6000.16386 (vista_rtm.061101-2205) 0.74%
6.0.6000.16386 (vista_rtm.061101-2205) 11.94%

Relationships

PE structurePE file structure
Show functions
Import table
advapi32.dll
RegisterServiceCtrlHandlerExW, SetServiceStatus
api-ms-win-core-errorhandling-l1-1-0.dll
UnhandledExceptionFilter, SetUnhandledExceptionFilter, GetLastError, SetLastError
api-ms-win-core-errorhandling-l1-1-1.dll
UnhandledExceptionFilter, SetUnhandledExceptionFilter, GetLastError, SetLastError
api-ms-win-core-handle-l1-1-0.dll
CloseHandle
api-ms-win-core-interlocked-l1-1-0.dll
InterlockedIncrement, InterlockedCompareExchange, InterlockedCompareExchange64, InterlockedExchange
api-ms-win-core-interlocked-l1-2-0.dll
InterlockedIncrement, InterlockedCompareExchange, InterlockedCompareExchange64, InterlockedExchange
api-ms-win-core-libraryloader-l1-1-0.dll
DisableThreadLibraryCalls
api-ms-win-core-libraryloader-l1-1-1.dll
DisableThreadLibraryCalls
api-ms-win-core-libraryloader-l1-2-0.dll
DisableThreadLibraryCalls
api-ms-win-core-misc-l1-1-0.dll
Sleep
api-ms-win-core-processthreads-l1-1-0.dll
GetCurrentProcessId, GetCurrentProcess, GetCurrentThreadId, TerminateProcess
api-ms-win-core-processthreads-l1-1-1.dll
GetCurrentThreadId, GetCurrentProcessId, TerminateProcess, GetCurrentProcess
api-ms-win-core-processthreads-l1-1-2.dll
GetCurrentThreadId, GetCurrentProcessId, GetCurrentProcess, TerminateProcess
api-ms-win-core-profile-l1-1-0.dll
QueryPerformanceCounter
api-ms-win-core-synch-l1-1-1.dll
Sleep
api-ms-win-core-synch-l1-2-0.dll
Sleep, AcquireSRWLockExclusive, InitializeSRWLock, ReleaseSRWLockExclusive, ReleaseSRWLockShared, AcquireSRWLockShared
api-ms-win-core-sysinfo-l1-1-0.dll
GetSystemTimeAsFileTime, GetTickCount
api-ms-win-core-sysinfo-l1-1-1.dll
GetSystemTimeAsFileTime, GetTickCount
api-ms-win-core-sysinfo-l1-2-0.dll
GetSystemTimeAsFileTime, GetTickCount
api-ms-win-core-sysinfo-l1-2-1.dll
GetSystemTimeAsFileTime, GetTickCount
api-ms-win-eventing-classicprovider-l1-1-0.dll
GetTraceEnableLevel, GetTraceEnableFlags, TraceMessage
api-ms-win-power-setting-l1-1-0.dll
PowerSettingRegisterNotification, PowerSettingUnregisterNotification
api-ms-win-service-core-l1-1-0.dll
RegisterServiceCtrlHandlerExW, SetServiceStatus
api-ms-win-service-core-l1-1-1.dll
SetServiceStatus, RegisterServiceCtrlHandlerExW
avrt.dll
AvRevertMmThreadCharacteristics, AvSetMmThreadCharacteristicsW
kernel32.dll
GetCurrentProcess, SetUnhandledExceptionFilter, TerminateProcess, InterlockedExchangeAdd, InterlockedCompareExchange64, InterlockedCompareExchange, GetLastError, SetLastError, InterlockedExchange, InterlockedIncrement, GetSystemTimeAsFileTime, GetCurrentProcessId, GetCurrentThreadId, GetTickCount, QueryPerformanceCounter, DisableThreadLibraryCalls, UnhandledExceptionFilter
ntdll.dll
NtCreateEvent, NtOpenEvent, NtCreatePrivateNamespace, NtOpenPrivateNamespace, RtlAddSIDToBoundaryDescriptor, RtlCreateBoundaryDescriptor, RtlInitUnicodeStringEx, NtAlpcCreatePort, NtCancelTimer, RtlInterlockedFlushSList, NtSetTimer, NtResetEvent, NtWaitForMultipleObjects, NtAlpcAcceptConnectPort, NtAlpcSendWaitReceivePort, AlpcGetMessageAttribute, AlpcInitializeMessageAttribute, RtlExitUserThread, RtlCreateUserThread, NtCreateTimer, NtQueryValueKey, memcpy, NtOpenKey, NtEnumerateKey, NtQueueApcThread, NtSetTimerResolution, NtWaitForSingleObject, NtSetSystemInformation, RtlInterlockedPushEntrySList, NtResumeThread, NtOpenThread, NtFreeVirtualMemory, NtAllocateVirtualMemory, RtlSetDaclSecurityDescriptor, NtDeletePrivateNamespace, RtlCreateAcl, RtlCreateSecurityDescriptor, RtlLengthSid, RtlSubAuthoritySid, RtlInitializeSid, RtlLengthRequiredSid, RtlCreateServiceSid, NtQueryPerformanceCounter, RtlCompareMemory, NtAlpcImpersonateClientOfPort, RtlGetCurrentProcessorNumber, _vsnwprintf, NtSetValueKey, RtlRandomEx, RtlUnwind, NtQueryTimerResolution, NtQuerySystemInformation, RtlAllocateHeap, RtlAcquirePrivilege, RtlFreeHeap, DbgPrompt, NtDeviceIoControlFile, NtOpenFile, NtQueryInformationProcess, NtReadVirtualMemory, NtOpenProcess, EtwLogTraceEvent, DbgPrintEx, EtwUnregisterTraceGuids, RtlDeleteBoundaryDescriptor, NtAlpcOpenSenderThread, NtQueryInformationThread, NtSetInformationThread, RtlInitializeSListHead, EtwRegisterTraceGuidsW, EtwGetTraceLoggerHandle, NtSetEvent, _wcsicmp, RtlAddAccessAllowedAce, RtlReleasePrivilege, NtClose, RtlNtStatusToDosError, NtDelayExecution, memset, DbgBreakPoint, NtTraceEvent, LdrGetDllFullName, RtlIntegerToUnicodeString, NtPowerInformation, TpAllocWait, TpSetWait, TpReleaseWait, TpWaitForWait, NtSetTimerEx, RtlAllocateAndInitializeSid, RtlFreeSid, NtAlertThread, ZwAlpcCancelMessage, ZwAlpcSendWaitReceivePort, ZwAlpcConnectPort, RtlWaitOnAddress, TpAllocAlpcCompletion, RtlInitUnicodeString, RtlWakeAddressAll, TpWaitForAlpcCompletion, ZwAlpcDisconnectPort, ZwClose, TpReleaseAlpcCompletion, ZwAlpcQueryInformation, vDbgPrintEx, RtlCaptureContext, memcmp
Export table
ServiceMain
ToServiceMain

mmcss.dll

Multimedia Class Scheduler Service by Microsoft

Remove mmcss.dll
Version:   6.2.8102.0 (winmain_win8m3.110823-1455)
MD5:   3424df4f7d81f560abbf85119e831d5f
SHA1:   b693566d3c056c94f89d7575e4851eb63b42c822
This is a Windows system installed file with Windows File Protection (WFP) enabled.

What is mmcss.dll?

The Multimedia Class Scheduler service (MMCSS) enables multimedia applications to ensure that their time-sensitive processing receives prioritized access to CPU resources. This service enables multimedia applications to utilize as much of the CPU as possible without denying CPU resources to lower-priority applications.

About mmcss.dll (from Microsoft)

“Multimedia Class Scheduler Service (MMCSS) is a Windows service that boosts the CPU as well as I/O priority of a thread. It allows an application to get prioritized access to CPU for time-sensitive pr”

DetailsDetails

File name:mmcss.dll
Publisher:Microsoft Corporation
Product name:Multimedia Class Scheduler Service
Description:Microsoft® Windows® Operating System
Typical file path:C:\Windows\System32\mmcss.dll
Original name:mmcss.dll.mui
File version:6.2.8102.0 (winmain_win8m3.110823-1455)
Product version:6.2.8102.0
Size:48 KB (49,152 bytes)
Build date:8/23/2011 6:14 PM
Digital DNA
PE subsystem:Windows Console
File packed:No
Code language:Microsoft Visual C# / Basic .NET
.NET CLR:Yes
.NET NGENed:No
More details

BehaviorsBehaviors

Hosted services
Runs as a shared service under the Windows svcHost
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'
  • Shared name is 'MMCSS'

Windows OS versionsDistribution by Windows OS

OS versiondistribution
Windows 7 Home Premium 36.50%
Windows 7 Ultimate 18.50%
Windows 8.1 11.00%
Windows 7 Professional 5.50%
Windows 8 5.00%
Windows 8.1 Pro 4.50%
Windows 8 Pro 4.50%
Windows Vista Home Premium 4.00%
Windows 7 Home Basic 2.00%
Windows 8.1 Pro with Media Center 1.50%
Windows 8 Single Language 1.50%
Windows 8.1 Single Language 1.00%
Windows Seven Black Edition 0.50%
Windows 8 Enterprise N 0.50%
Windows Vista Home Basic 0.50%
Windows Developer Preview 0.50%
Windows 8.1 Enterprise 0.50%
Windows 7 Enterprise 0.50%
Windows Se7en Titan 0.50%
Windows 8 Pro with Media Center 0.50%
Windows Vista Business 0.50%
21 other Windows OS version

Distribution by countryDistribution by country

United States installs about 41.41% of Multimedia Class Scheduler Service.

OEM distributionDistribution by PC manufacturer

PC Manufacturerdistribution
Dell 21.64%
Hewlett-Packard 17.54%
ASUS 17.16%
Lenovo 10.45%
Toshiba 9.70%
Acer 8.21%
Sony 3.73%
Intel 2.24%
Alienware 1.87%
GIGABYTE 1.49%
Medion 1.49%
MSI 1.49%
Samsung 1.12%
Gateway 0.75%
Compaq 0.75%
American Megatrends 0.37%
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