Since other computers can access SQL Server properly, this issue can occur due to the network connection between Windows 7 computer and Windows 2008 R2 server, we may need to involve the network administrator to help us troubleshoot the network connection
issue. Currently, please try to ping Windows 2008 R2 server on Windows 7 computer side. Additionally, please make sure the SQL Server login you use with Windows 7 computer is valid. If it still fails to connect to SQL Server, please post the detail error message
here for analysis. There are some other troubleshooting steps on the following link, you can also refer to them.