SQL Server Management Studio Express is a limited version that authorize access to SQL Server Databases (Express or not).

Analysis, Reporting, Integration Services or SQL Server Agent are not available from this Express version.

Most important features from  "Databases" and "Security" trees are available to create and modify databases and security accounts (but not roles).

The following features are also available:

- Generate scripts

- Attach/Detach

- Backup/Restore 

- Activity monitor

...whereas "Maintenance plans" and "Logs" can't be opened.

The prerequisites are at least : 

Microsoft Data Access Components (MDAC)                3.70.1146
Microsoft MSXML                                        3.0 5.0 6.0
Microsoft Internet Explorer                            6.0.2800.1106
Microsoft .NET Framework                               2.0.50727.42