OK, I'll try to be as descriptive as possible.
Two days ago, we experienced a computer crash. We had to recover a corrupted registry that prevented Windows XP from starting. After resolving the issue and finally being able to get Windows to work, I tried to start Archicad. Despite never removing the protection key, I got an error message that says:
Protection key not found or not valid (128).
I thought that perhaps by reinstalling Archicad, the problem might be solved. However, Archicad does not appear when I go to Add/Remove Programs. What should I do? Can I remove the Archicad files manually and try to start from scratch? The protection key has functioned on other computers, so I don't think it's the key. The USB port also recognizes the key when I plug it in. Thanks to anyone who can assist me! If you need more info, let me know.