Error: "Could Not Find Installable ISAM"

Place single quotes around the Extended Properties:

OleDbConnection oconn =     new OleDbConnection(        @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties='Excel 8.0;HDR=YES;IMEX=1;';");

Try it, it really works.

Try putting single quotes around the data source:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source='D:\ptdb\Program Tracking Database.mdb';

The problem tends to be white space which does have meaning to the parser.

If you had other attributes (e.g., Extended Properties), their values may also have to be enclosed in single quotes:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source='D:\ptdb\Program Tracking Database.mdb'; Extended Properties='Excel 8.0;HDR=YES;IMEX=1;';

You could equally well use double quotes; however, you'll probably have to escape them, and I find that more of a Pain In The Algorithm than using singles.

Just use Jet OLEDB: in your connection string.it solved for me.

an example is below:

"Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=False;Data Source=E:\Database.mdb;Jet OLEDB:Database Password=b10w"