Example, to see if KB983590 is installed:
systeminfo | find "KB983590"
But what if I wanted to find out if more then one KB was installed?
You can also use /i for case insensitive searching. Run findstr /? for even more options.
If you want to search for just a subset of patches, use spaces in between entries:
I'd go the route of 'find' instead of 'findstr' (simpler/easier)
you'll get your list.
use for /f to organize the data easier such as
that will get rid of the numbered sequence from the beginning of each line.
if you want only the KB#####, change the tokens value to only 2 without the asterisk, and change the ending ECHO to just ECHO %F
will throw it on your desktop as a .TXT file
of course if you want it ina batch file, make sure your %F has an extra % (%%F)