title: Visual studio 2010 Service Pack 1 Installation Error: Another install of this package is already running
body: <p>I am having a very hard time installing Visual Studio 2010 Service Pack 1 on a Windows XP machine. I downloaded and installed a Visual Studio 2010 trial without trouble. But when I downloaded and tried to install Visual Studio Service Pack 1 I got the error message shown below. </p>
  
  <p>Once I got the error, I re-booted (to kill any processes) and opened add/remove programs, which showed that SP1 was installed on my machine. I tried to uninstall SP1 and got the exact same error message that I got during the install!? I then tried to uninstall SP1 using Revo uninstaller and got the same message again. </p>
  
  <p>in my copy of visual studio, intellisense doesn't pick up the @ tag for the razor syntax (SP1 added that support for that syntax)--so I know the installation was unsuccessful</p>
  
  <p>Where can I go from here? </p>
  
  <p><img src="https://i.stack.imgur.com/yTgBe.png" alt="enter image description here"></p>