Hi gang
Ran into a small problem here.
We're testing the deployment of Symantec's Enterprise Vault Outlook
client.
It's a MSI file, and the instruction to deploy via GP is pretty simple.
So, I created a Computer-based policy, Software Install --> Assigned,
and point it to \\fileserver\share\evclient.msi.

It worked on exactly one computer. On the computer that works, we can
see the software being installed on boot up (just before the login
screen), and once we logged in, the client appears on Outlook.

On the computer that doesn't work, boots up as normal, nothing on
Outlook. Under Control Panel --> Add/Remove program, we can see the
program being installed there though. Nothing under C:\Program Files\,
however. We've confirmed this on few different PCs (just to rule out the
possibility of one weird PC)

Gpresult command on one of the PCs that didn't have the program
installed:

COMPUTER SETTINGS
------------------
CN=JAFTEST2,OU=Test GPO,DC=acer,DC=edu,DC=au
Last time Group Policy was applied: 8/20/2008 at 10:45:29 AM
Group Policy was applied from: acerfr.acer.edu.au
Group Policy slow link threshold: 500 kbps

Applied Group Policy Objects
-----------------------------
WSUS - Test Group
EV Client Deployment
Default Domain Policy

The following GPOs were not applied because they were filtered out
-------------------------------------------------------------------
Screensaver Lock
Filtering: Not Applied (Empty)

Local Group Policy
Filtering: Not Applied (Empty)

The computer is a part of the following security groups:
--------------------------------------------------------
BUILTIN\Administrators
Everyone
BUILTIN\Users
NT AUTHORITY\NETWORK
NT AUTHORITY\Authenticated Users
JAFTEST2$
Domain Computers

As you can see, EV Client Deployment GP was applied.

2. No meaningful logs in Event Viewer.
3. The software appeared to be installed under Add/Remove Software but
nowhere to be seen in the HD.

I've turned on Windows Explorer MSI logging and disabled Fast Logging in
Windows XP.
So, I did another test. I uninstalled Enterprise Vault client via
Add/Remove Program, removed the computer from the OU, rebooted.

Then I logged back in, checked the list, Enterprise Vault was in the
Add/Remove Program again. Removed it again, rebooted. Logged back in,
this time, software isn't on the list.

I put the computer back into the OU, rebooted the PC twice (MS
documentation said we'll need to reboot twice to get Software
installation working), lo and behold it worked. I've tried the same
method on two PCs, it worked. I need to figure out what happened.
Blaargh.