shell32.dll
This file is not a system component: windows itself, not a download. Restore it from the source that installed it rather than downloading a replacement.
Do not download this DLL on its own
Searching for a missing DLL by name leads to sites that hand you that single file. It is one of the oldest and most effective malware delivery methods there is, and a system DLL from an unknown source is indistinguishable from a deliberately modified one. There is never a legitimate reason to obtain a runtime component that way.
What it is
The Windows shell library: it draws the file dialogs, the icons, the context menus and much of what you think of as the desktop. Every version of Windows contains it.
Where you see it: Icon corruption, broken Open and Save dialogs, and old programs written against a much older Windows.
A shell32.dll error is almost never a missing file. It is usually either system file damage, which "sfc /scannow" followed by "DISM /Online /Cleanup-Image /RestoreHealth" repairs, or a program asking for a function that does not exist in your version of Windows, which no replacement file can provide. Copying a shell32.dll from another Windows version is a reliable way to break the desktop entirely.
Why there is nothing to download here
There is no verified download we can offer for this one, because installing a file is not the fix. The steps above are what actually resolves it. That distinction matters: the sites ranking for this file name are selling a download that would not have helped even if it were safe.