When checking the database size for an SQL Server 2005 Express database,
I notice that the Windows file size is around 103 MB, while
"Properties" in Management Studio Express says it's 156 MB.

I restarted the SQL Server service before checking the Windows size
to make sure everything is written to disk.

Which one is correct? For SQL Server 2000, I noticed that the Windows
file size corresponds to the database size in Taskpad.

(Select * from sysfiles gives some totally different value.)