Do not use NoNav or add/remove programs to uninstall v10.1.6
I recently migrated my SAV CE from v10.0.2 to v10.1.6. When I performed the migration on my servers everything looked ok at first but then I noticed that on my primary server SAV kept kicking off installs one after another. At one point I saw at least six installation processes running at the same time. It was like a Chinese fire drill trying to cancel them all. This would happen any time I tried to open the SAV GUI or touch anything else that involved SAV. I called Symantec support and the engineer had me put the disk into the cd drive on the server and try to complete the install, it reported that the install was already completed. Yet SAV continued to try to install itself all by itself over and over again. The engineer then told me that I would need to uninstall and reinstall the product because something must have been corrupt with the initial install. First I had to move all my connected clients from the primary server to the secondary server and then uninstall the primary server. When I tried to uninstall through add/remove programs I got an error message telling me that there was an incomplete install and that I needed to let that finish before I could uninstall. Reboots didn't help this either. The engineer then sent me the NoNav utiity to run on the server to remove the program. This is when the real horror started. In subsequent phone conversations that I've had with Symantec engineers and an escalation manager it appears there is a fault in 10.1.6 that, when installed, associates itself with a lot of things that it has no business doing. As a result the NoNav utility wiped out most of my MS Exchange files and executables along with an as yet unknown number of other things. My NSI Double Take replication software no longer works, I have screwed up print queues and a whole range of problems. The consensus of opinion from the Symantec engineers and myself is that the server has to be rebuilt from scratch. They told me that it was not NoNav's fault because add/remove programs would have done the same thing.
To sum this up, according to Symantec, there is a known fault with the installer. They say it only effects the server installs. If you uninstall the product v10.1.6 using either the NoNav utility or add/remove programs it will remove a great many files that it shouldn't such as program executables belonging to other software and the operating system.
If you need to uninstall this product you'll need to do it manually with registry edits and manual file removal otherwise you're likely to have huge problems as I am having now.