Getting error while installing Exchange 2013

Hi,

I am trying to install Exchange 2013 on Microsoft Windows Server 2008 R2 Standard. I have installed all required prerequisites which are necessary to install before performing Exchange installation. But still I am getting the following error...

Error:
The NetBIOS name of the computer doesn't match the DNS host name. Ensure that the NetBIOS name isn't truncated due to the 15-character limit.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ComputerNameDiscrepancy.aspx

Error:
All Exchange servers in the organization are above this version of Exchange: EXC2013-124.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.AllServersOfHigherVersionRule.aspx

Warning:
Setup can't detect a Send connector with an address space of '*'. Mail flow to the Internet may not work properly.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.NoConnectorToStar.aspx

I will really appreciate your response in this regard.

 Sajid