Before you start make a back up copy of YourProject.ism
1. Remove any events or conditions from your bad radiobutton group
2. Take note of the name of the radio button group and the property name that the radio button group uses.
3. From the the file menu Select export to text file. This will create YourProject.isv
4. Remove the RadioButtonGroup
Open YourProject.isv in a good text editor
search for lines containing RadioButtonGroup
You should find lines starting somthinh like
RadioGroupName CONTROL C1234 1 NextControlName ##StringID## etc.
If you find yours.take note of the control ID eg. C745.
Delete this line, Search for Delete all other lines referring to "C745"
5. Remove The Radio Buttons
Search for the term RADIOBUTTON
You should find an area containing somthing like
If you find yours, take note of the RadioButton ID eg R746. Search for all references to R746 in the .ISV file and delete them.
6. Reimport your changes to InstallShield. From the File menu choose open, change "Files Of Type" Drop down list to .ISV files and open your new .ISV. Make a trivial change so that InstallShield will let you save. Save as normal.
7. Make sure your changes have no unplesant side effects.
This is a dangerous procedure. I do not recommend casual editing of the .ISV file.