diff --git a/viofs/svc/virtiofs.cpp b/viofs/svc/virtiofs.cpp
index 2f245b56..bf782960 100644
--- a/viofs/svc/virtiofs.cpp
+++ b/viofs/svc/virtiofs.cpp
@@ -29,7 +29,7 @@
 
 #pragma warning(push)
 // '<anonymous-tag>' : structure was padded due to alignment specifier
-#pragma warning(disable: 4324) 
+#pragma warning(disable: 4324)
 // nonstandard extension used : nameless struct / union
 #pragma warning(disable: 4201)
 // potentially uninitialized local variable 'Size' used
@@ -46,6 +46,7 @@
 #include <sys/stat.h>
 #include <wtsapi32.h>
 #include <cfgmgr32.h>
+#include <securitybaseapi.h>
 
 #include <map>
 #include <string>
@@ -129,6 +130,8 @@ struct VIRTFS
     UINT32  OwnerUid{ 0 };
     UINT32  OwnerGid{ 0 };
 
+    BOOL IsRunningAsLocalSystem{ false };
+
     // Maps NodeId to its Nlookup counter.
     std::map<UINT64, UINT64> LookupMap{};
 
@@ -486,39 +489,91 @@ static DWORD FindDeviceInterface(PHANDLE Device)
     return ERROR_SUCCESS;
 }
 
-static VOID UpdateLocalUidGid(VIRTFS *VirtFs, DWORD SessionId)
+static NTSTATUS FspToolGetTokenInfo(HANDLE Token,
+    TOKEN_INFORMATION_CLASS TokenInformationClass, PVOID *PInfo)
 {
-    PWSTR UserName = NULL;
-    LPUSER_INFO_3 UserInfo = NULL;
-    DWORD BytesReturned;
-    NET_API_STATUS Status;
-    BOOL Result;
+    PVOID Info{ NULL };
+    DWORD Size;
+    NTSTATUS Result;
 
-    Result = WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE, SessionId,
-        WTSUserName, &UserName, &BytesReturned);
+    if (GetTokenInformation(Token, TokenInformationClass, 0, 0, &Size))
+    {
+        Result = STATUS_INVALID_PARAMETER;
+        goto exit;
+    }
 
-    if (Result == TRUE)
+    if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
     {
-        Status = NetUserGetInfo(NULL, UserName, 3, (LPBYTE *)&UserInfo);
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
 
-        if (Status == NERR_Success)
-        {
-            // Use an account from local machine's user DB as the file's
-            // owner (0x30000 + RID).
-            VirtFs->LocalUid = UserInfo->usri3_user_id + 0x30000;
-            VirtFs->LocalGid = UserInfo->usri3_primary_group_id + 0x30000;
-        }
+    Info = HeapAlloc(GetProcessHeap(), 0, Size);
+    if (NULL == Info)
+    {
+        Result = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    if (!GetTokenInformation(Token, TokenInformationClass, Info, Size, &Size))
+    {
+        Result = FspNtStatusFromWin32(GetLastError());
+        goto exit;
+    }
+
+    *PInfo = Info;
+    Result = STATUS_SUCCESS;
+
+exit:
+    if (!NT_SUCCESS(Result))
+        SafeHeapFree(Info);
+
+    return Result;
+}
+
+static VOID UpdateLocalUidGid(VIRTFS *VirtFs, DWORD SessionId)
+{
+    NTSTATUS Result;
+
+    HANDLE Token{ NULL };
+    TOKEN_USER *Uinfo{ NULL };
+    TOKEN_PRIMARY_GROUP *Ginfo{ NULL };
 
-        if (UserInfo != NULL)
+    if (VirtFs->IsRunningAsLocalSystem)
+    {
+        if (!WTSQueryUserToken(SessionId, &Token))
         {
-            NetApiBufferFree(UserInfo);
+            VirtFs->LocalUid = 0;
+            VirtFs->LocalGid = 0;
+            DBG("Failed to open a process token as LocalSystem; Error=%d", GetLastError());
+            return;
         }
     }
-
-    if (UserName != NULL)
+    else if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &Token))
     {
-        WTSFreeMemory(UserName);
+        VirtFs->LocalUid = 0;
+        VirtFs->LocalGid = 0;
+        DBG("Failed to open a process token; Error=%d", GetLastError());
+        return;
     }
+
+    Result = FspToolGetTokenInfo(Token, TokenUser, (PVOID *)&Uinfo);
+    if (!NT_SUCCESS(Result))
+       goto exit;
+
+    Result = FspToolGetTokenInfo(Token, TokenPrimaryGroup, (PVOID *)&Ginfo);
+    if (!NT_SUCCESS(Result))
+       goto exit;
+
+    Result = FspPosixMapSidToUid(Uinfo->User.Sid, &(VirtFs->LocalUid));
+    Result = FspPosixMapSidToUid(Ginfo->PrimaryGroup, &(VirtFs->LocalGid));
+
+    DBG("Local UID=%u, local GID=%u", VirtFs->LocalUid, VirtFs->LocalGid);
+
+exit:
+    SafeHeapFree(Uinfo);
+    SafeHeapFree(Ginfo);
+    CloseHandle(Token);
 }
 
 static UINT32 PosixUnixModeToAttributes(VIRTFS *VirtFs, uint64_t nodeid,
@@ -2535,6 +2590,7 @@ NTSTATUS VIRTFS::SubmitDestroyRequest()
 
 NTSTATUS VIRTFS::Start()
 {
+    HANDLE Token{ NULL };
     NTSTATUS Status;
     DWORD SessionId;
     FILETIME FileTime;
@@ -2549,8 +2605,24 @@ NTSTATUS VIRTFS::Start()
     SessionId = WTSGetActiveConsoleSessionId();
     if (SessionId != 0xFFFFFFFF)
     {
+        // Will fail if we are not the LocalSystem user.
+        IsRunningAsLocalSystem = WTSQueryUserToken(SessionId, &Token);
+
+        if (IsRunningAsLocalSystem)
+        {
+            CloseHandle(Token);
+        }
+        else
+        {
+            DBG("The service %s was not run as the LocalSytem user", FS_SERVICE_NAME);
+        }
+
         UpdateLocalUidGid(this, SessionId);
     }
+    else
+    {
+        DBG("Failed to get SessionID!");
+    }
 
     GetSystemTimeAsFileTime(&FileTime);
 
@@ -2768,10 +2840,10 @@ static NTSTATUS DebugLogSet(const std::wstring& DebugLogFile)
 static NTSTATUS SvcStart(FSP_SERVICE* Service, ULONG argc, PWSTR* argv)
 {
     std::wstring DebugLogFile{};
-    ULONG DebugFlags = 0;
+    ULONG DebugFlags{ 0 };
     std::wstring MountPoint{ L"*" };
     VIRTFS *VirtFs;
-    NTSTATUS Status = STATUS_SUCCESS;
+    NTSTATUS Status{ STATUS_SUCCESS };
     DWORD Error;
 
     if (argc > 1)