Try whith generate a Partha-datourceDS.xml with this:
<datasources>
<local-tx-datasource>
<jndi-name>Partha</jndi-name>
<connection-url>jdbc:sqlserver://Partha_server:1433;databasename=Partha</connection-url>
<driver-class>com.microsoft.jdbc.sqlserver.SQLServerDriver</driver-class>
<user-name>Partha</user-name>
<password>123456</password>
<min-pool-size>5</min-pool-size>
<max-pool-size>20</max-pool-size>
<idle-timeout-minutes>5</idle-timeout-minutes>
</local-tx-datasource>
</datasources>
And put the file Partha-datourceDS.xml in Path > C:/jboss-5.1.0.GA/server/default/deploy/