If you want to export a list of updates installed on a Windows 2008 server, there is a built in tool to do this.
Use the WMIs Command-line interface (WMIC) to export this list.
On the command line:
wmic qfe get /format:csv > C:\updates.csv
You can use these other format options:
CSV | HFORM | HTABLE | LIST | MOF | RAWXML
HFORM/HTABLE are HTML
LIST is Tab Delimited
RAWXML is XML