The iPlayer received the approval of the BBC Trust on 30 April 2007 and an open beta for Windows XP and Windows Server 2003 was launched at midnight on 27 July 2007, when it was announced that only a fixed number of people would be able to sign up for the service, with a controlled increase in users over the summer. The BBC had been criticised for saying that the iPlayer would 'launch' on 27 July 2007, when what was on offer was simply an extension of the beta to an open beta, admitting more users in a controlled manner. This was done reportedly to allow British ISPs and the BBC to gauge the effect of the iPlayer traffic on the Internet within the UK.