Unable to enable SQL dependency for ASP.NET MVC application

Unable to enable SQL dependency for ASP.NET MVC application

When I am running this query on my database
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO "Keith\ASPNET"
I am getting below error
Cannot find the user 'Keith\ASPNET', because it does not exist or you do
not have permission.
I am using ASP.NET Sqldependency.
My Sql Server Name is Keith. SSMS is showing KEITH(SQL Server 11.0.2100 -
Keith\Keith)
When I open my IIS the root on the tree is showing Keith(Keith\Keith)
Below are some more information, if required in SSMS I have below logins
##MS_PolicyEventProcessingLogin##
##MS_PolicyTsqlExecutionLogin##
Keith\Keith
NT AUTHORITY\SYSTEM
NT Service\MSSQLSERVER
NT SERVICE\ReportServer
NT SERVICE\SQLSERVERAGENT
NT SERVICE\SQLWriter
NT SERVICE\winmgmt
sa
and database has following Users
dbo
guest
INFORMATION_SCHEMA
sys
My connection string
<add name="MyEntities"
connectionString="metadata=res://*/Models.Model1.csdl|res://*/Models.Model1.ssdl|res://*/Models.Model1.msl;provider=System.Data.SqlClient;provider
connection string=&quot;data source=Keith;initial catalog=MyDb;integrated
security=True;MultipleActiveResultSets=True;App=EntityFramework&quot;"
providerName="System.Data.EntityClient" /></connectionStrings>
Please let me know if any other information is required from my side.