I've been prompted twice in the last few days to upgrade from MSAS to
Defender, both installs have failed. Pursuing it further the second time it
seems the problem is that MSAS can't be un-installed, neither by defender
installation nor manually. The AntiSpyware.msi file can't be found.

How do I un-install MSAS so I can install defender?

Hello Rick,

Look here:
Subject: Windows Defender Installer Information Error 1905.Module C:
5/5/2006 2:05 PM PST
By: RickJ
In: microsoft.private.security.spyware.install

http://support.microsoft.com/kb/555375


"Rick" wrote:

> I've been prompted twice in the last few days to upgrade from MSAS to
> Defender, both installs have failed. Pursuing it further the second time it
> seems the problem is that MSAS can't be un-installed, neither by defender
> installation nor manually. The AntiSpyware.msi file can't be found.
>
> How do I un-install MSAS so I can install defender?

The symptoms RickJ encountered don't seem very similar to what I encountered
(I never saw that error message) but I suppose the same fix might work. In
any case I found a simpler solution. I discovered I still had a copy of
MicrosoftAntiSpywareInstall.exe from which MSAS was installed. I ran this
install again and it ran successfully. I was then able to un-install MSAS
from the control panel. This wouldn't work before. Once MSAS was gone,
defender installed without a problem.

"Engel" wrote:

> Hello Rick,
>
> Look here:
> Subject: Windows Defender Installer Information Error 1905.Module C:
> 5/5/2006 2:05 PM PST
> By: RickJ
> In: microsoft.private.security.spyware.install
>
> http://support.microsoft.com/kb/555375
>
>
> "Rick" wrote:
>
> > I've been prompted twice in the last few days to upgrade from MSAS to
> > Defender, both installs have failed. Pursuing it further the second time it
> > seems the problem is that MSAS can't be un-installed, neither by defender
> > installation nor manually. The AntiSpyware.msi file can't be found.
> >
> > How do I un-install MSAS so I can install defender?