When you log on, some Microsoft Installer (MSI) packages may be reinstalled?

This feature is the result of using a roaming profile and implementing the Delete cached copies of roaming profiles Group Policy at Computer Configuration\Administrative Templates\System\Logon.

The MSI stores information about the package at HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\<SID>. This information is only stored in the local cached profile and is NOT copied back to the server when the user logs off. If the locally cached profile is deleted, the information is lost.