Login failed for user 'NT AUTHORITY\\NETWORK SERVICE'

I got this error when deploying my WCF + linq to SQL service to IIS. This happens because IIS runs under NT AUTHORITY\\NETWORK SERVICE. There are a couple of solutions here:

• change IIS service to run under another user.
• setup impersonation (complicated but ideal)
  
• grant Network service access to the database ( quick but insecure)
  

Just to get it running on your test server you can use option three as explained below:

• Just open up SSMS
• log into database server
• expand Security -> logins.
• Right click logins and select new login
  
• search login name
  
• type in "network service"
• in server roles check "public" and "sysadmin"
• in user mapping select your database and give it "owner" and "public" rights
• Click OK and your are all set

Enjoy!