I installed the entire CS5 Web Premium suite on my windows 32-bit PC. All applications except Flash builder and Flash player are installed, I can open and use them with no problems, however, Flash Builder and player will not install. The error messages (abbreviated because it's 7 pages of error messages) indicates that there is a problem with the ARKCreateDirectoryCommand and the installer was unable to create a directory, unable to delete files and much more. The error codes specific to flash builder are 14921, 14919, 14918 14856, 14855, 14854, 23, 4 , 3, 2, and 1. I cannot run this as administrator although I am a privileged user and am able to install applications otherwise.
One possibility is that you're running into a limitation we have with certain types of roaming user profiles, if your user documents folder is stored on a network share instead of locally, and there is no access to its parent folder.
If you send me your full install log file zip (or gz format), I'll be able to see more clearly where it's failing. You can find instructions for locating that here, though from your message it looks as if you might already have that log handy:
If you send that as an attachment to me at cagruss [at adobe dot com], I'll have a look.