Create a query based on your Table and drag the necessary fields to the QBE grid including the Primary Key field. Save it. Create your Report and base it on the Query you just made and save it. Next create a form with a Text box and set the Text box format to numerical if your Primary key is numerical or Text if it is text. Create a Command button using the Wizard to open your newly created Report. Save the form. Go back to your new query and in the Criteria line of the column with the Primary key put in code like this: [Forms]![NameOfFormYouJustCreated]![NameOfFieldOnThatForm]
Now open your form, type in a Primary key in the field and then click the button to open the report.
I might suggest a Combo box that shows your Primary keys instead of the text box as it is more accurate and does not require you to remember the Primary key.
HTH,
Jack