It is most likely due to not having the Excel OLEDB/ODBC driver not installed on the Windows Server 2008 R2 computer. This ODBC-driver is not standard but it gets installed when you install Office and you can also download it.
Both where to find the drivers and the alternative to using the OLEDB/ODBC driver is mentioned in this thread:
I just solved the problem. the problem was not of office driver; the happend is that the connection string uses a ODBC named Excel Files and i didn't have this created on my server. It exists in my personal computer because when isntall the office it create this driver (I don't remenber i have create on my pc).
From i created it connected correctly.
Go to ODBC administrator and in the User DSN tab, create new ODBC named Excel Files.