Vista - Guests OS hang VM Additions 13.820 on VS05 R2 Ent SP1

I encountered several hours of downtime attempting to update the VM
Additions from 13.552 to 13.820 on Windows Server 2003 guest OS's. The
parent server is Windows Server 2003 Enterprise x64 SP2 and is up to date
running Virtual Server 2005 R2 Enterprise SP1 + KB948515 + MS09-033
(KB969856). When I attempt to install the new additions on the guests, it
uninstalls the existing ones and reboots the guest OS. When the guest OS
restarts without any additions, it is so slow (55 min to press ctrl-alt-del
logon screen!) it is impossible to log on and complete the installation of
the new additions. I had to revert to my backup VHD drives to get the guest
OS's operational again. How should I complete the upgrades? I tried
booting the guest OS in safe mode, but the additions cannot be installed
since the Windows Installer Service does not run in safe mode

I have already reviewed these articles:
http://technet.microsoft.com/en-us/l...8WS.10%29.aspx
http://technet.microsoft.com/en-us/l...8WS.10%29.aspx

Any suggestions yet? Can the VM Additions be installed manually by
copying files to offline VHD's and editing the registry files (dangerous and
time consuming w/o a proper procedure)? Or is this a know issue with
MS09-033 so I can call Microsoft PSS for support?

<Mltwwlco@newsgroup> wrote in message
news:u9tmq$DIKHA.4024@newsgroup

On Thu, 20 Aug 2009 14:10:35 -0700, <Mltwwlco@newsgroup> wrote:
My guess is that you have virtual scsi drives? Without the additions,
performance is as you'd describe.

--
Cheers,
Steve Jain, Virtual Machine MVP
http://vpc.essjae.com/