Problem with restoring database.

I Got This Problem when i try to restore the database :(

Spoiler:

TITLE: Microsoft SQL Server Management Studio Express
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An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.Express.ConnectionInfo)

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ADDITIONAL INFORMATION:

Cannot open backup device 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Backup\ACCOUNT_DBF.bak'. Operating system error 5(Access is denied.).
RESTORE HEADERONLY is terminating abnormally. (Microsoft SQL Server, Error: 3201)

For help, click: Source: MSSQLServer ID: 3201 (SQL Server 09.00.4035) - Events And Errors Message Center: Message Details

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BUTTONS:

OK
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hope you can help me

Maybe a corrupted backup?

Restore failed for Server - RESTORE HEADERONLY is terminating abnormally - Asp.Net, C#, SQL Blog

how can i fix the backup ?