To store data in use, Windows Vista uses a temporary folder on the hard drive where it is installed. If you have two hard drives, you better save this file to make your disk faster.

Follow the tips below:
  1. With Windows Explorer, navigate to your second drive.
  2. Create a new folder called Temp for example.
  3. Click the Start button and then click Control Panel.
  4. Click the System icon and maintenance.
  5. Then click System.
  6. In the left pane, click the Advanced System Settings task.
  7. Then click the Environment Variables button in the window that opens.
  8. Select the TEMP variable and click Edit.
  9. In the Value field of the variable, enter the path to the folder you just created on another drive, D: \ Temp in this example. Click Ok.
  10. Repeat the same operation for the variable TMP.
  11. Then press OK twice. Restart your computer to apply the change.