Launch Task Manager and end all Adobe related processes , then instead of deleting , try renaming Adobe Photoshop CS 2 folder to Old-Adobe Photoshop CS 2 and check.
Also you may run Microsoft Fix it tool , and if present remove Photoshop CS 2. it will detect if there are any remnants of Photoshop CS 2 left on computer.
http://go.microsoft.com/?linkid=9779673
Becky , will do one thing , simply download Photoshop CS 2 setup file and try to install instead of complete Creative Suite.
I know it is bit confusing to provide instructions in cases like this without visualization , even you had followed all steps exactly as per mentioned the link I provided earlier, so we will try with Individual installation once instead of Suite.