VBA declare statements for Windows API calls showing red font (error)

The 64 bit operating system really has nothing to do with VBA, the issue is which version of Office you are using.

I believe Martin's changes should resolve the issue.  What is strange is that MS decided to use a variable named Win64 rather than Off64 to determine which version of Office you are running.

It's normal in those conditional compile sections for one section (the one that doesn't apply hopefully) to show up in red.  That won't be a problem though since those lines will never be compiled or executed due to the conditional compile directives.

Are you running this code in a 64-bit Office installation?

• 64-bit Visual Basic for Applications overview | Microsoft Docs
• Compiler constants (VBA) | Microsoft Docs

Just compile your code...its normal for dual bitness declarations..

I agree with John that the declarations which are not valid for your current environment will normally display as red, but as John said, those lines should not be compiled if you are using the correct conditional compilation tests (thus Win64 OR VBA7) that Martin mentioned.

Private WithEvents mcTree As clsTreeView
#If Win64 Or VB7 Then
    Private Declare PtrSafe Function LockWindowUpdate Lib "user32" (ByVal hWndLock As LongPtr) As Long
#Else
    Private Declare Function LockWindowUpdate Lib "user32" (ByVal hwnd As Long) As Long
#End If

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#If VBA7 Then

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