1. If you uninstall the old version of sunview manually, and then try to install new version, maybe you will have this problem

2. It means you didn't uninstall the old version completely,  so some files still save in the registry.

3. open the regedit.exe on the Windows

4. go to HKEY_LOCAL_MACHINESOFTWAREWOW6432Node, find the folder “vmSystem” , and delete it directly. then you can install the new version correctly.