I wrote this script recently to extract the percentage free disk space on all servers in a SCOM environment, and email it.
The file is available for download here:
Update the fields between the <>, save as a .vbs file and run as a scheduled task. Not a very elegant solution, but far quicker than having to configure the disk space report in SCOM reporting. And, as always, I suck at commenting, so feel free to leave a comment if you get stuck.
SQL query was refined using a bored colleague at work with some time to bash through the DB and the following sources: