The creation of workgroup in Access 2007 is different from how it is usually done in Access 2000 and Access 2002-2003.
The steps to follow for creating WorkGroup are:
Open a DB in Access or enable macros in existing DB.
Open Create tab, go to Other group select Macro and click on Macro in drop down list.
Click on Show All Actions in the Show/Hide group in design tab.
Select ‘Run Command’ in Action Column in Macro1 tab.
Select ‘WorkgroupAdminstrator’ in the Command list.
Save the DB.
Click on Run in Tools group.
After clicking on “Run”, a dialog box opens up with options to create a new WorkGroup or join an existing group.