In a pinch? Here's the page to the download links for all versions of QuickBooks 2010, and links to the older versions too. Just click on the link to download the file to your desktop, and then open it to run the installation program.
P.S. You'll need your license and product number!. If you're moving QuickBooks from one computer to another, just open QuickBooks, then type the "Ctrl" and "1" keys at the same time. Your product information window will pop up, and the top second and third lines are your license and product number