You cannot install a Creative Suite 5 application from a pen, or flash drive. The Adobe Illustrator CS5, Photoshop CS5, or InDesign CS5 installer asks for a disc and then fails to install.
After you have copied the image file onto your computer's desktop, double click the *.img (Ma OS), or *iso (Windows) file and start the installation.
Keep the installer in this Adobe [product] CS5 folder. Then, start the installation.