First try with command line "tnsping" that there is really connectivity between laptop and database. That exclude firewall problems, database down, incorrect installation etc.
If there are multiple Oracle versions, one can use an ODBC datasource. That allows to select the driver. QlikView is slower with Oracle ODBC versus Oracle OLE DB, but still works ok.
Hi ..thanks for the pointer. This clarified that the default home is the 64 bit driver. We will remove the 32bit QV Client and the 32 Bit Oracle Drivers and then install the 64 bit QV Client. It seems that the error message above is known in Oracle when the path to application trying to connect contains a Parenthesis (). The QV 32 bit Clients sits in a folder called c:\Program files (X86)\