[cesarb]

There are some things Wine doesn't do. Last time I checked, it didn't fully implement DCOM, so it couldn't be used for OPC (OLE for Process Control) and similar. And the use case in the parent comment might need Windows 98 because (other than Windows ME which everyone pretends didn't exist) it was the last DOS-based version of Windows; AFAIK, Wine does have some MS-DOS emulation, but it's limited to what some Windows 3.x software might need.

[ekianjo]

you can always contract codeweavers for it to do more.

[anthk]

Wine can use Windows' DLL's just fine.

[rpeden]

Unless they use the bits of DCOM where Wine's DCOM implementation isn't quite compatible with Microsoft's, which was the OP's point.

[chungy]

By using Microsoft's DCOM implementation ("the Windows DLLs"), you bypass using Wine's DCOM entirely.