right-click on the Excel Connection Manager

select properties

click on the + sign by "Expressions"

click on the elipsis ...

select "ConnectionString" in the Property drop-down

copy and past exactly, including quotes, no spaces:

...

I am having the same problem.....

creating linked server, I specify:

provider: Microsoft OLE DB provider for ODBC drivers

product name: ODBC system DSN

Data Source: ODBC system DSN

I do not specify anything else...