How do I update a column in a row in salesforce

SELECT Name, ProfileId, Id, Username FROM User this is the select query to retrive data in Force.com explorer
this is successfully retriving data.

But, I am trying to update from WinForm Application using following query 

Update Profile set Name='Standard User' where Id='00e90000001XQiYAAW'

 Now I am getting following error 

ERROR:MALFORMED_QUERY: unexpected token: Update – 

 thanks in advance