From LedHed's Wiki
Check which updates are installed via command line (or PSExec)
wmic qfe list brief /format:texttablewsys > "c:\temp\hotfix.txt"
or
wmic qfe list brief /format:htable > "c:\temp\hotfix.html"
Alternatively you can use the netdiag tool in verbose mode
netdiag -v
or more specifically
netdiag -v | findstr "KB########"
Where KB####### represents the KB article number you're looking for