programs/explorer/desktop.c: Add error checking

[Frank Richter]

On 01.12.2007 16:20, Vitaly Lipatov wrote:
> UuidToStringW from legacy (DCOM95) rpcrt4.dll returns RPC_S_CANNOT_SUPPORT, 
> works only ANSI version.
> 
> Changelog:
> Add return codes checking for UuidCreate and UuidToStringW

Do users still commonly install that legacy DCOM? If so, it may be
better to replace UuidToStringW with UuidToStringA so the
initialize_display_settings() function continues working (it looks
somewhat important, but not sure if it really is).

-f.r.