I just recently upgraded my KIS2012 to 2013. What I did was download, from the Kaspersky site the KIS2013. Then uninstalled 2012 with the option to keep/save the Activation codes. I think I rebooted, then installed the 2013, and was all set after it updated the database. Prior to that, I was paranoid that I lose everything, not have the activation code, and in general have one of my worst nightmares. -- Went through without a hitch. Hope this helps.
I think once it has uninstalled the older version, there is no roll back function. For updates yes, roll back works fine, but for a product update I'd think it would create more issues than just replacing everything - or in this case, nothing was returned to the old state.
I maybe wrong, but I wonder if the older installer files were there, if they had of been it may have had something to work with.
This is hear say as I've not tested it, but without a 2012 installer folder it would have a hard time even if it was to roll back correctly.
