Cannot Connect to Microsoft SQL Server, System.Transactions missing?

Anyone please help. I have a deadline and I am unable to connect to any Microsoft SQL Server on my development box. Not sure what happened but all of a sudden when I attempt to connect to any Microsoft SQL Server, I get the following error:

Could not load file or assembly 'System.Transactions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies.开发者_如何学C The module was expected to contain an assembly manifest. (System.Data)

Anyone PLEASE help! I am running Windows 7 x64 with Visual Studio 2008/2010, SQL Server Express 2008 R2

This can be caused by different kinds of issues.

You probably have classes that reference this assembly but you didn't add a reference to your project.

Or it can be more complicated as an example here.

Try running gacutil -I "C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Transactions.dll"

System.Transaction should be part of .NET framework and it should be installed in the GAC. I suspect your update somehow removed it from the GAC.

Check to see if system.transaction is in the GAC.

Open Windows Explorer Navigate to c:\windows\assembly Check if System.Transaction is there If not, you may need to reinstall the assembly into the GAC.

http://forums.asp.net/t/1145885.aspx/1?New+error+Could+not+load+file+or+assembly+