Have you tried regular uninstallation procedures and the removal tool mentioned here?
I do this all day at least 5 days a week and here is the best resolution that I can find for the issue with the Radial Point software from the old AT&T Internet Security Suite.
1.) NEVER REMOVE THE OLD AT&T SECURITY SUITE FROM ADD/REMOVE PROGRAMS!!! Here is a link for downloading the un-installer software for the old AT&T Security Suite... just follow the directions and that will remove the old security suite completely.
2.) After you run the removal tool the machine will restart and you may still have the AT&T Internet Security Wizard in your "all programs" list... If you do still have the security wizard listed on the all programs list... DON'T USE ADD/REMOVE PROGRAMS TO REMOVE THE AT&T SECURITY WIZARD!!! Please go to the programs list and use the uninstall utility that is under the AT&T Internet Security Wizard and choose "Uninstall"
After doing the above you can click on the following link to download and install the new AT&T Internet Security Suite powered by McAfee and everything should work fine:
The reason that you will not want to use "add/remove programs" is because the uninstall sometimes will not completely work from "add/remove programs". If the software is not completely uninstalled then the new security suite will not install and you get the error you asked about.
Now if you have already used "add/remove programs" to uninstall the old AT&T Security Wizard you may have problems when you install the new AT&T Security Suite powered by McAfee. Your machine may still show the Radial Point software at the McAfee install but when you go to remove the Radial Point software your machine will tell you that it can not be found... Here is what I have found to work:
1.) Go to "my computer" and right click your "C:\" drive and then left click explore
2.) Find the folder for AT&T and double click it
3.) Look for a folder with AT&T Security Wizard and delete that folder
4.) Finally after deleting that folder you can then try downloading and installing the new AT&T Security Suite powered by McAfee from the link above.
If all else fails you can always call AT&T Tech Support at 1-888-321-2375
also, if all those steps do not work...this is what I did....
look in add/remove programs and uninstall any other antivirus stuff you may have installed before installing Internet Security Suite (the original one). I had a couple of instances of LiveUpdate and Symantec that was not uninstalled during my last ISS install. I removed those programs and then the new installation went in right away.
So basically look through the computer's program files and remove ALL instances of other security software, then install ISS by McAfee
Some security software (anti-virus, firewalls, etc.) will not function correctly with other similar programs installed. Uninstalling previous security software, including any existing McAfee programs, should prevent any conflicts from occurring during or after installation.
Note: Common security software to look for (not a complete list): Norton, Symantec, Panda, Zone Labs (or Zone Alarm), Trend Micro, AVG, and PC-cillin remove its programs from control panel as well as its files and folders from C:/programs files and common files ; by which the installation should go on fine.
Do report back if you encounter any issues while installing McAfee with the exact error message.