you should use WMI to get this information. the registry key locations could (and did) change between windows versions.
here's the WMI command line to get the list:
C:\ wmic qfe list full
WMI also has a completely scriptable interface: http://msdn.microsoft.com/en-us/library/ms974579.aspx
Where in the registry can I find the location that shows all installed hotfixes? In XP it was pretty straight forward - HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\hotfix\KBXXXXX
This doesn't exist in Vista. Any ideas on where to look? I need this to write an EPA scan expression in Citrix to verify the user has a certain hotfix installed after SP1.
Windows Vista Business SP1 is what I am using.
Thanks in advance for any responses!