We need more information.
For starters, the OS, the version of the applications, and the exact error message, or a screen shot of the error dialog.
I think this is a permissions issue. Are you using an account with Adminsitrator or restricted permissions?
Are the the applications fully patched? That's helps some users with this error. If you can launch any of the CS5.5 programs you should be ale to launch the Adobe Updater from the Help menu, otherwise try downloading the latest patches manually for each application from the Adobe.com website.
Finally, see http://helpx.adobe.com/photoshop-elements/kb/licensing-problem.html This particular article is for Photoshop Elements, but it appears to be generic in application.
If all else fails, uninstall, run the clean tool (CS Cleaner Tool for installation problems | CCM, CS6, CS5.5, CS5, CS4, CS3) and reinstall.