When you install 3.5SP1 on a machine without win7/2008, the installer needs to connect to the Internet, go down some stuff, and be super slow, no matter what full or incomplete version you download.
Solution:
Download the full installation package for 3.5SP1 on the official website.
http://www.microsoft.com/zh-cn/download/confirmation.aspx?id=25150
2. When the download is complete, run dotnetfx35.exe/x under the command line and extract to a directory (e.g. D: "), a D:" WCU directory is generated
3. Enter the Wcu\dotnetframework under the decompression directory
4. Run Dotnetfx35setup.exe/lang:enu from the command line
5.OK resolution.
This article is from the "Sun Liming Technology Blog" blog, make sure to keep this source http://sunliming.blog.51cto.com/982606/1573066
Microsoft. NET Framework 3.5 SP1 installation slow, fast offline installation method