MSI error 1603 when installing or upgrading Inventory Solution, Inventory fails to install or upgrade.
Another symptom is that after installation or upgrade none of the Inventory Solution console items are visible or available.

MSI Error code 1603

The security on the Inventory folder in the install path becomes corrupt, leaving no access from any account but System.

To allow Inventory to install properly, run through the following steps:

1. Uninstall Inventory via Symantec Installation Manager (SIM), if it shows as installed.
2. Go to the Inventory folder, default location: C:\Program Files\Altiris\Inventory.
3. Right-click on the folder and choose Properties.
4. Click on the security tab.
5. Click "Change" next to owner.
6. Enter the Application Identity account to take ownership.
7. You may get prompted to force security down the folder structure. Choose yes to do so.
8. Once the owner has been changed, delete the Inventory folder.
9. Now reinstall Inventory Solution via SIM.