Access as ODBC data source error

Hi

I have created MS Access ODBC data source and connected with it. but when i trie to add it as data source in MS BI Data Gate way, i am getting following error: "The 'Driver' property with value '{Microsoft Access Driver (*.mdb, *.accdb)}' doesn't correspond to an installed ODBC driver.".

Below is my connection string:

Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=C:\dat207x\PowerBI.accdb;

please any quick help?....