diff --git a/dll/win32/shell32/CDefView.cpp b/dll/win32/shell32/CDefView.cpp
index d2c41bf5b30..3ea7e4f2eb8 100644
--- a/dll/win32/shell32/CDefView.cpp
+++ b/dll/win32/shell32/CDefView.cpp
@@ -518,7 +518,7 @@ public:
         return wc;
     }
 
-    virtual WNDPROC GetWindowProc()
+    virtual WNDPROC GetWindowProc() override
     {
         return WindowProc;
     }
@@ -1059,7 +1059,7 @@ HRESULT CDefView::GetDetailsByFolderColumn(PCUITEMID_CHILD pidl, UINT FoldCol, S
 {
     // According to learn.microsoft.com/en-us/windows/win32/shell/sfvm-getdetailsof
     // the query order is IShellFolder2, IShellDetails, SFVM_GETDETAILSOF.
-    HRESULT hr;
+    HRESULT hr = E_FAIL;
     if (m_pSF2Parent)
     {
         hr = m_pSF2Parent->GetDetailsOf(pidl, FoldCol, &sd);
@@ -1230,6 +1230,7 @@ void CDefView::ColumnListChanged()
             break;
         HRESULT foldCol = MapListColumnToFolderColumn(listCol);
         assert(SUCCEEDED(foldCol));
+        DBG_UNREFERENCED_LOCAL_VARIABLE(foldCol);
         AppendMenuItem(m_hMenuArrangeModes, MF_STRING,
                        DVIDM_ARRANGESORT_FIRST + listCol, lvc.pszText, listCol);
     }
@@ -3373,7 +3374,7 @@ HRESULT CDefView::LoadViewState()
             m_LoadColumnsList = NULL;
         }
     }
-    m_sortInfo.bLoadedFromViewState = !fallback && m_LoadColumnsList && cvs.SortColId != LISTVIEW_SORT_INFO::UNSPECIFIEDCOLUMN;
+    m_sortInfo.bLoadedFromViewState = !fallback && m_LoadColumnsList && (int)cvs.SortColId != LISTVIEW_SORT_INFO::UNSPECIFIEDCOLUMN;
     m_sortInfo.bColumnIsFolderColumn = TRUE;
     m_sortInfo.Direction = cvs.SortDir > 0 ? 1 : -1;
     m_sortInfo.ListColumn = cvs.SortColId;
diff --git a/dll/win32/shell32/CDefaultContextMenu.cpp b/dll/win32/shell32/CDefaultContextMenu.cpp
index 17cffeef96f..65363744934 100644
--- a/dll/win32/shell32/CDefaultContextMenu.cpp
+++ b/dll/win32/shell32/CDefaultContextMenu.cpp
@@ -219,7 +219,7 @@ class CDefaultContextMenu :
         STDMETHOD(GetSite)(REFIID riid, void **ppvSite) override;
 
         // IServiceProvider
-        virtual HRESULT STDMETHODCALLTYPE QueryService(REFGUID svc, REFIID riid, void**ppv)
+        virtual HRESULT STDMETHODCALLTYPE QueryService(REFGUID svc, REFIID riid, void**ppv) override
         {
             return IUnknown_QueryService(m_site, svc, riid, ppv);
         }
diff --git a/dll/win32/shell32/CRecycleBinCleaner.cpp b/dll/win32/shell32/CRecycleBinCleaner.cpp
index e8cdaf31dbe..72a99cfc9d6 100644
--- a/dll/win32/shell32/CRecycleBinCleaner.cpp
+++ b/dll/win32/shell32/CRecycleBinCleaner.cpp
@@ -10,7 +10,7 @@
 WINE_DEFAULT_DEBUG_CHANNEL(shell);
 
 
-CLSID CLSID_RecycleBinCleaner = { 0x5ef4af3a, 0xf726, 0x11d0, 0xb8, 0xa2, 0x00, 0xc0, 0x4f, 0xc3, 0x09, 0xa4 };
+CLSID CLSID_RecycleBinCleaner = { 0x5ef4af3a, 0xf726, 0x11d0, { 0xb8, 0xa2, 0x00, 0xc0, 0x4f, 0xc3, 0x09, 0xa4 } };
 
 struct CRecycleBinCleaner :
     public CComObjectRootEx<CComSingleThreadModel>,
diff --git a/dll/win32/shell32/debughlp.cpp b/dll/win32/shell32/debughlp.cpp
index f57d399789b..79e314c8b00 100644
--- a/dll/win32/shell32/debughlp.cpp
+++ b/dll/win32/shell32/debughlp.cpp
@@ -452,7 +452,7 @@ const char * shdebugstr_guid( const struct _GUID *id )
         }
 
             return wine_dbg_sprintf( "\n\t{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x} (%s)",
-                 id->Data1, id->Data2, id->Data3,
+                 (UINT)id->Data1, id->Data2, id->Data3,
                  id->Data4[0], id->Data4[1], id->Data4[2], id->Data4[3],
                  id->Data4[4], id->Data4[5], id->Data4[6], id->Data4[7], name ? name : "unknown" );
 }
diff --git a/dll/win32/shell32/dialogs/drive.cpp b/dll/win32/shell32/dialogs/drive.cpp
index 5de42ddfa3f..37175a05b83 100644
--- a/dll/win32/shell32/dialogs/drive.cpp
+++ b/dll/win32/shell32/dialogs/drive.cpp
@@ -374,7 +374,7 @@ InitializeFormatDriveDlg(HWND hwndDlg, PFORMAT_DRIVE_CONTEXT pContext)
 {
     WCHAR szDrive[] = { WCHAR(pContext->Drive + 'A'), ':', '\\', '\0' };
     WCHAR szText[120], szFs[30];
-    INT cchText;
+    SIZE_T cchText;
     ULARGE_INTEGER TotalNumberOfBytes;
     DWORD dwIndex, dwDefault;
     UCHAR uMinor, uMajor;
@@ -398,8 +398,6 @@ InitializeFormatDriveDlg(HWND hwndDlg, PFORMAT_DRIVE_CONTEXT pContext)
     SendMessageW(pContext->hWndTipTrigger, STM_SETICON, (WPARAM)hIco, 0);
 
     cchText = GetWindowTextW(hwndDlg, szText, _countof(szText) - 1);
-    if (cchText < 0)
-        cchText = 0;
     szText[cchText++] = L' ';
     szFs[0] = UNICODE_NULL;
     if (GetVolumeInformationW(szDrive, &szText[cchText], _countof(szText) - cchText, NULL, NULL, NULL, szFs, _countof(szFs)))
diff --git a/dll/win32/shell32/dialogs/filetypes.cpp b/dll/win32/shell32/dialogs/filetypes.cpp
index a2206ad9fe9..851e7fa2f72 100644
--- a/dll/win32/shell32/dialogs/filetypes.cpp
+++ b/dll/win32/shell32/dialogs/filetypes.cpp
@@ -334,6 +334,7 @@ InitializeDefaultIcons(PFILE_TYPE_GLOBALS pG)
     {
         int idx = ImageList_AddIcon(pG->himlSmall, pG->hDefExtIconSmall);
         ASSERT(idx == 0);
+        DBG_UNREFERENCED_LOCAL_VARIABLE(idx);
     }
 }
 
diff --git a/dll/win32/shell32/dialogs/view.cpp b/dll/win32/shell32/dialogs/view.cpp
index 4dd3e8801bc..87f4c270497 100644
--- a/dll/win32/shell32/dialogs/view.cpp
+++ b/dll/win32/shell32/dialogs/view.cpp
@@ -249,7 +249,7 @@ ViewTree_InsertAll(HWND hwndTreeView)
 static BOOL
 ViewTree_LoadTree(HKEY hKey, LPCWSTR pszKeyName, DWORD dwParentID)
 {
-    DWORD dwIndex;
+    DWORD dwIndex = ~0UL;
     WCHAR szKeyName[64], szText[MAX_PATH], *pch;
     DWORD Size, Value;
     PVIEWTREE_ENTRY pAllocated;
diff --git a/dll/win32/shell32/droptargets/CFSDropTarget.cpp b/dll/win32/shell32/droptargets/CFSDropTarget.cpp
index bc84e7ec939..48d9c4f97a3 100644
--- a/dll/win32/shell32/droptargets/CFSDropTarget.cpp
+++ b/dll/win32/shell32/droptargets/CFSDropTarget.cpp
@@ -544,7 +544,7 @@ HRESULT CFSDropTarget::_DoDrop(IDataObject *pDataObject,
             bLinking = TRUE;
     }
 
-    if (SUCCEEDED(pDataObject->QueryGetData(&fmt)))
+    if (SUCCEEDED(hr = pDataObject->QueryGetData(&fmt)))
     {
         hr = pDataObject->GetData(&fmt, &medium);
         TRACE("CFSTR_SHELLIDLIST\n");
@@ -698,7 +698,7 @@ HRESULT CFSDropTarget::_DoDrop(IDataObject *pDataObject,
         _ILFreeaPidl(apidl, lpcida->cidl);
         ReleaseStgMedium(&medium);
     }
-    else if (SUCCEEDED(pDataObject->QueryGetData(&fmt2)))
+    else if (SUCCEEDED(hr = pDataObject->QueryGetData(&fmt2)))
     {
         FORMATETC fmt2;
         InitFormatEtc (fmt2, CF_HDROP, TYMED_HGLOBAL);
diff --git a/dll/win32/shell32/folders/CRecycleBin.cpp b/dll/win32/shell32/folders/CRecycleBin.cpp
index 5051c619d7e..b335fa36ac5 100644
--- a/dll/win32/shell32/folders/CRecycleBin.cpp
+++ b/dll/win32/shell32/folders/CRecycleBin.cpp
@@ -186,11 +186,13 @@ static inline LPCWSTR GetItemRecycledFullPath(const BBITEMDATA &Data)
     return (LPCWSTR)((BYTE*)&Data + Data.RecycledPathOffset);
 }
 
+#if UNUSED && FALSE
 static inline LPCWSTR GetItemRecycledFileName(LPCITEMIDLIST pidl, const BBITEMDATA &Data)
 {
     C_ASSERT(BBITEMFILETYPE & PT_FS_UNICODE_FLAG);
     return (LPCWSTR)((LPPIDLDATA)pidl->mkid.abID)->u.file.szNames;
 }
+#endif
 
 static int GetItemDriveNumber(LPCITEMIDLIST pidl)
 {
diff --git a/dll/win32/shell32/shellmenu/CMenuSite.cpp b/dll/win32/shell32/shellmenu/CMenuSite.cpp
index 7596237b596..9ccb55d42d5 100644
--- a/dll/win32/shell32/shellmenu/CMenuSite.cpp
+++ b/dll/win32/shell32/shellmenu/CMenuSite.cpp
@@ -85,7 +85,7 @@ HRESULT STDMETHODCALLTYPE CMenuSite::AddBand(IUnknown * punk)
 
 HRESULT STDMETHODCALLTYPE CMenuSite::EnumBands(UINT uBand, DWORD* pdwBandID)
 {
-    if (uBand == -1ul)
+    if (uBand == UINT(-1))
         return GetBandCount();
 
     if (uBand != 0)
diff --git a/dll/win32/shell32/shellrecyclebin/recyclebin_v5.cpp b/dll/win32/shell32/shellrecyclebin/recyclebin_v5.cpp
index c32f9c8d630..08146caca74 100644
--- a/dll/win32/shell32/shellrecyclebin/recyclebin_v5.cpp
+++ b/dll/win32/shell32/shellrecyclebin/recyclebin_v5.cpp
@@ -559,7 +559,8 @@ RecycleBin5_Create(
     LPWSTR FileName; /* Pointer into BufferName buffer */
     LPCSTR DesktopIniContents = "[.ShellClassInfo]\r\nCLSID={645FF040-5081-101B-9F08-00AA002F954E}\r\n";
     INFO2_HEADER Info2Contents[] = { { 5, 0, 0, 0x320, 0 } };
-    DWORD BytesToWrite, BytesWritten, Needed;
+    DWORD BytesToWrite, BytesWritten;
+    SIZE_T Needed;
     HANDLE hFile = INVALID_HANDLE_VALUE;
     HRESULT hr;
 
@@ -623,7 +624,7 @@ RecycleBin5_Create(
         hr = HRESULT_FROM_WIN32(GetLastError());
         goto cleanup;
     }
-    BytesToWrite = strlen(DesktopIniContents);
+    BytesToWrite = (UINT)strlen(DesktopIniContents);
     if (!WriteFile(hFile, DesktopIniContents, (DWORD)BytesToWrite, &BytesWritten, NULL))
     {
         hr = HRESULT_FROM_WIN32(GetLastError());
diff --git a/dll/win32/shell32/wine/classes.c b/dll/win32/shell32/wine/classes.c
index 6138fdac267..e6f23070c2e 100644
--- a/dll/win32/shell32/wine/classes.c
+++ b/dll/win32/shell32/wine/classes.c
@@ -254,7 +254,7 @@ BOOL HCR_RegOpenClassIDKey(REFIID riid, HKEY *hkey)
 {
 	char	xriid[50];
     sprintf( xriid, "CLSID\\{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}",
-                 riid->Data1, riid->Data2, riid->Data3,
+                 (UINT)riid->Data1, riid->Data2, riid->Data3,
                  riid->Data4[0], riid->Data4[1], riid->Data4[2], riid->Data4[3],
                  riid->Data4[4], riid->Data4[5], riid->Data4[6], riid->Data4[7] );
 
diff --git a/dll/win32/shell32/wine/shellord.c b/dll/win32/shell32/wine/shellord.c
index 063678000b0..376d96e7b16 100644
--- a/dll/win32/shell32/wine/shellord.c
+++ b/dll/win32/shell32/wine/shellord.c
@@ -334,6 +334,7 @@ VOID WINAPI SHGetSetSettings(LPSHELLSTATE lpss, DWORD dwMask, BOOL bSet)
     else
     {
         DWORD read = 0, data, cb, dummy = 0;
+        DBG_UNREFERENCED_LOCAL_VARIABLE(dummy);
         if (SHELL_GlobalCounterChanged(&g_ShellStateCounter, SHELL_GCOUNTER_SHELLSTATE))
             g_CachedSSF = 0;
 
diff --git a/dll/win32/shlwapi/ordinal.c b/dll/win32/shlwapi/ordinal.c
index 3646c54153c..17223417254 100644
--- a/dll/win32/shlwapi/ordinal.c
+++ b/dll/win32/shlwapi/ordinal.c
@@ -633,7 +633,7 @@ INT WINAPI SHStringFromGUIDA(REFGUID guid, LPSTR lpszDest, INT cchMax)
   TRACE("(%s,%p,%d)\n", debugstr_guid(guid), lpszDest, cchMax);
 
   sprintf(xguid, "{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
-          guid->Data1, guid->Data2, guid->Data3,
+          (UINT)guid->Data1, guid->Data2, guid->Data3,
           guid->Data4[0], guid->Data4[1], guid->Data4[2], guid->Data4[3],
           guid->Data4[4], guid->Data4[5], guid->Data4[6], guid->Data4[7]);