There are two questions in this thread:
1. Help! I uninstalled Symantec's security suite and now I can't run Windows
This *should* not be happening with Vista. There are protections against
third-party vendors turning off Security Center. It is certainly possible to
turn them off, but that should be considered a hostile action. That's not at
all to say that Symantec wouldn't do so.
I _believe_ the reason you are having this problem is a flawed uninstaller
in Symantec's AV suite. Most likely they leave the Windows Security Center
service disabled after they uninstall. You need to re-enable the service for
Windows Security Center. This KB article tells you how to do it on XP:
. The instructions are very similar for
Vista, but you can type services.msc in the search dialog on the start menu
instead of in the Run menu.
2. I have OneCare. Do I still need the Windows Firewall?
No. In fact, you can't use it. OneCare comes with its own firewall.
I find the fact that OneCare comes with its own firewall confusing and a
poor use of resources. The built-in firewall is better, less intrusive, and
faster. It would be nice if Microsoft were to finally stop building the same
functionality in three different places just because they have the people to
> I have the same issue on my computer too, although I installed Windows Live
> OneCare. I have a firewall and antispam etc through that program so do I
> still need my Windows firewall turned on too? Do I even need to use the
> Security Center? I am confused about this issue.