Error Message "The Temp Directory '' Is Not a Valid Directory" during Isolated Shell Install

One of our customers is not able to install studio in his windows vista machine, and he sent a screenshot that says "The Temp Directory <path> is Not a Valid Directory" during Isolated Shell Install. Based on the screenshot he sent, we understand that the installer is trying to download the Visual Studio Shell 2010 (Isolated) from the internet and then install it. The download is complete but the downloaded files are not located, when the  installer is trying to run them. We kind of traced down the problem to be an issue with the TMP and the TEMP environment variable. (Am not still 100% sure).May be when there are comments, I will check.

To resolve this issue, verify that the TMP environment variable points to a valid folder. By default, this is the %Userprofile%\Local Settings\Temp folder. Also make sure that the %UserProfile% environment variable is valid.
To change the TMP environment variable to point to a valid folder:

  1. Right-click My Computer, and then click Properties.
  2. Click the Advanced tab.
  3. Click Environment Variables.
  4. Click the TMP variable, and then click Edit. Edit all instances of the TMP and TEMP environment variables so that they point to a valid folder to which you have access.
  5. Click OK, and then close all the open dialog boxes.
  6. Verify that the folder that you are using for the TMP and TEMP environment variables is accessible and has enough free space.