You can also delete all tables from database using only MSSMS UI tools (without using SQL script). Sometimes this way can be more comfortable (especially if it is performed occasionally)
I do this step by step as follows:
- Select ‘Tables’ on the database tree (Object Explorer)
- Press F7 to open Object Explorer Details view
- In this view select tables which have to be deleted (in this case all of them)
- Keep pressing Delete until all tables have been deleted (you repeat it as many times as amount of errors due to key constraints/dependencies)