Solution for installing SQL SERVER 2008 that must use the "Role management Tools" error (GO)

There was an error when installing SqlServer2008 on the server (Win2008)- You must install or configure the Microsoft. NET Framework 3.5 SP1 using the Role management tool. At first thought it was not installed 3.5, later looked at the server has installed the VS2010, and then ruled out this possibility. Google a bit, and then find a solution to the problem. (I've been going to the server to install and deploy a variety of things and then have problems \("▔□▔)/)

1, the problem appears as follows, pop up a prompt box:



2. Follow the prompts to open the role management tool first. The Server Manager , Administrative Tools , Control Panel , opens in turn. I cut a picture as follows:


3. In the " Service Manager ", click " features " in the left menu, then click on the Add feature in the right functional area, and tick the ". NET Framework 3.5.1 Feature" in the " Add Features Wizard " window that pops up. ", then click on the" Install "button to install it. As follows:


4, after the successful installation, you can install SqlServer2008 bird ╰ (￣▽￣) ╮ ...