You can quickly collect this from the command prompt using WMIC (as long as you are using an operating system newer than Windows 2000).
This command-line utility (Wmic.exe) is used to access Windows Management Instrumentation (WMI) and saves you having to write a script to gather information by means of WMI. Wmic.exe can only be used by the local system administrators.
To collect the list of installed hotfixes, run something like:
WMIC QFE LIST FULL /Format:HTable > C:\Temp\HotfixList.HTM
and look at HotfixList.htm afterwards.