diff --git a/releasenotes/notes/fix_logging_win_installer-c750541f4fd49b77.yaml b/releasenotes/notes/fix_logging_win_installer-c750541f4fd49b77.yaml
new file mode 100644
index 00000000000000..d462b6a88d38bc
--- /dev/null
+++ b/releasenotes/notes/fix_logging_win_installer-c750541f4fd49b77.yaml
@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fix some string logging in the Windows installer.
diff --git a/tools/windows/install-help/cal/FinalizeInstall.cpp b/tools/windows/install-help/cal/FinalizeInstall.cpp
index 360bbc1cc96e8e..b927103f7cacc2 100644
--- a/tools/windows/install-help/cal/FinalizeInstall.cpp
+++ b/tools/windows/install-help/cal/FinalizeInstall.cpp
@@ -368,8 +368,8 @@ UINT doFinalizeInstall(CustomActionData &data)
         if (!bRet)
         {
             DWORD lastErr = GetLastError();
-            std::string lastErrStr = GetErrorMessageStr(lastErr);
-            WcaLog(LOGMSG_STANDARD, "CreateSymbolicLink: %s (%d)", lastErrStr.c_str(), lastErr);
+            auto lastErrStr = GetErrorMessageStrW(lastErr);
+            WcaLog(LOGMSG_STANDARD, "CreateSymbolicLink: %S (%d)", lastErrStr.c_str(), lastErr);
         }
         else
         {
diff --git a/tools/windows/install-help/cal/TargetMachine.cpp b/tools/windows/install-help/cal/TargetMachine.cpp
index ec684695b931da..e62bdfbf8d2b7c 100644
--- a/tools/windows/install-help/cal/TargetMachine.cpp
+++ b/tools/windows/install-help/cal/TargetMachine.cpp
@@ -214,7 +214,7 @@ DWORD TargetMachine::DetectDomainInformation()
                 return nErr;
             }
             _dcFlags = dcInfo->Flags;
-            WcaLog(LOGMSG_STANDARD, "Domain Controller is %s", IsReadOnlyDomainController() ? "Read-Only" : "Writable");
+            WcaLog(LOGMSG_STANDARD, "Domain Controller is %S", IsReadOnlyDomainController() ? L"Read-Only" : L"Writable");
             NetApiBufferFree(dcInfo);
         }
     }
diff --git a/tools/windows/install-help/cal/customaction.h b/tools/windows/install-help/cal/customaction.h
index 5da76ba3f8b270..8d9b9a6057d4e7 100644
--- a/tools/windows/install-help/cal/customaction.h
+++ b/tools/windows/install-help/cal/customaction.h
@@ -118,17 +118,19 @@ UINT doUninstallAs(UNINSTALL_TYPE t);
 
 // see https://stackoverflow.com/a/45565001/425565
 // Template ErrType can be HRESULT (long) or DWORD (unsigned long)
-template <class ErrType> std::string GetErrorMessageStr(ErrType errCode)
+template<class ErrType> std::wstring GetErrorMessageStrW(ErrType errCode)
 {
     const int buffsize = 4096;
-    char buffer[buffsize];
+    wchar_t buffer[buffsize];
     const DWORD len =
-        FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
+        FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
                        nullptr, // (not used with FORMAT_MESSAGE_FROM_SYSTEM)
                        errCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), &buffer[0], buffsize, nullptr);
     if (len > 0)
     {
-        return std::string(buffer, len);
+        return std::wstring(buffer, len);
     }
-    return "Failed to retrieve error message string.";
+    std::wstringstream wsstr;
+    wsstr << L"Failed to retrieve error message string for code " << errCode;
+    return  wsstr.str();
 }
diff --git a/tools/windows/install-help/cal/stopservices.cpp b/tools/windows/install-help/cal/stopservices.cpp
index bdb14fe371e558..0527ee6ede5b7c 100644
--- a/tools/windows/install-help/cal/stopservices.cpp
+++ b/tools/windows/install-help/cal/stopservices.cpp
@@ -881,8 +881,8 @@ int uninstallServices(CustomActionData &data)
         DWORD rbret = services[i].destroy(hScManager);
         if (rbret != 0)
         {
-            std::string lastErrStr = GetErrorMessageStr(rbret);
-            WcaLog(LOGMSG_STANDARD, "Failed to uninstall service %s (%d)", lastErrStr.c_str(), rbret);
+            auto lastErrStr = GetErrorMessageStrW(rbret);
+            WcaLog(LOGMSG_STANDARD, "Failed to uninstall service %S (%d)", lastErrStr.c_str(), rbret);
         }
     }
     WcaLog(LOGMSG_STANDARD, "done uinstalling services");
diff --git a/tools/windows/install-help/cal/userrights.cpp b/tools/windows/install-help/cal/userrights.cpp
index 63524af4015767..2fcc3823521ffd 100644
--- a/tools/windows/install-help/cal/userrights.cpp
+++ b/tools/windows/install-help/cal/userrights.cpp
@@ -321,14 +321,12 @@ DWORD AddUserToGroup(PSID userSid, wchar_t *groupSidString, wchar_t *defaultGrou
     memset(&lmi0, 0, sizeof(LOCALGROUP_MEMBERS_INFO_0));
     lmi0.lgrmi0_sid = userSid;
 
-    std::string asciiname;
-
     getGroupNameFromSidString(groupSidString, defaultGroupName, groupname);
     WcaLog(LOGMSG_STANDARD, "Attempting to add to group %S", groupname.c_str());
     nErr = NetLocalGroupAddMembers(NULL, groupname.c_str(), 0, (LPBYTE)&lmi0, 1);
     if (nErr == NERR_Success)
     {
-        WcaLog(LOGMSG_STANDARD, "Added ddagentuser to %s", asciiname.c_str());
+        WcaLog(LOGMSG_STANDARD, "Added user to %S", groupname.c_str());
     }
     else if (nErr == ERROR_MEMBER_IN_GROUP || nErr == ERROR_MEMBER_IN_ALIAS)
     {
@@ -352,7 +350,7 @@ DWORD DelUserFromGroup(PSID userSid, wchar_t *groupSidString, wchar_t *defaultGr
     lmi0.lgrmi0_sid = userSid;
 
     getGroupNameFromSidString(groupSidString, defaultGroupName, groupname);
-    WcaLog(LOGMSG_STANDARD, "Attempting to remove from group %s", groupname.c_str());
+    WcaLog(LOGMSG_STANDARD, "Attempting to remove from group %S", groupname.c_str());
     nErr = NetLocalGroupDelMembers(NULL, L"Performance Monitor Users", 0, (LPBYTE)&lmi0, 1);
     if (nErr == NERR_Success)
     {