I'm installing Unity 4.0(3) with an off-box Exchange server. When I try to install Unity on the Unity server, I double click the language, click Next, then I get a "Setup can not upgrade from a version older than 3.0" error. This is a lab setup, but what did I do wrong on this one? I'm using the UnityInstall account to install it. the account was not a member of the Domain Admins group, so I put it there but still the same problem. It doesn't matter what account I use, I get the same error. Thanks for any help.
looks like we did not really do a clean install(delete partition and format) but just inserted the Windows OS CD and this just re-copy the system files and which does not wipe out the registry.
This can be fixed using following options
1.Download the unity uninstall utility from www.ciscounitytools.com and clean uninstall unity and try again
2 delete following key from registry HKLM/Active voice. Also delete "commserver" folder and in AD, delete the Unity folder,reboot and try again