PasswordHash NULL problem

[thedougster]

When I try to save a new (inserted) record in an SQL database, I get the following System.Runtime.InteropServices.ExternalException message:

Cannot insert the value NULL into column 'PasswordHash', table 'AdventureWorks.Person.Contact'; column does not allow nulls.
INSERT fails.
The statement has been terminated.

I have to either find out how to insert an appropriate value into the PasswordHash column OR make SQL Server Management Studio allow NULL in the PasswordHash column.

I discovered I could do the latter in SQL Server Management Studio via:

expand table | expand Columns | right-click PasswordHash column | click Modify | in lower right frame: toggle Allow Nulls from No to Yes

On doing so and then attempting to exit SQL Server Management Studio, I got a dialog box saying:

Save changes to the following items?
SQL Server Objects
<Server name>.AdventureWorks - Person.Contact

Clicking Yes elicited the following message:

Saving changes is not permitted. The changes you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created.

Contact (Person)

SQL Server Management Studio's onboard Help says I can override the "Prevent saving changes that require the table to be re-created" setting via:

Tools | Options | Designers | Table and Database Designers | Prevent saving changes that require table re-creation

I can try this, but I wonder if it might be dangerous. If for whatever reason the table can't be re-created, could I possibly destroy the original table in the process and then have to reinstall the AdventureWorks database? I don't want to have to do that, since for some unknown reason I had a very difficult time installing it the first time.

And ultimately, I don't want to sacrifice encryption, as I suspect might be the case if I allowed PasswordHash to be NULL.

So here are my two questions:
1. Could it be dangerous to try to re-create the table?
2. How do I get an appropriate value to put in the PasswordHash column?

For what it's worth, I'm working in a 32-bit environment with the following software:

SQL Server 2008 Express with Advanced Services
database: SQL2008 AdventureWorks (schema.table: Person.Contact)
SQL Server 2008 Management Studio Express
Visual C# 2008 Express