The general form of a WMI query is as follows:

selects "<property> from <class>" of wmi

For instance, if you wanted to query the serial number of a computer, you would have to know that this information can be found in the SerialNumber property of the Win32_Bios class. Here is what the query would look like:

Using the Fixlet Debugger (QnA) tool on the system;

Q: selects "SerialNumber from Win32_Bios" of wmi
A: SerialNumber=DMHLX42

If you wanted the query to return just the value of the property and not its name, you would say:

Q: string value of selects "SerialNumber from Win32_Bios" of wmi
A: DMHLX42

To find a specific property using WMI, you will need to sort through the WMI for information, it is very well-documented. Links to all available WMI classes with their properties can be found here:

http://msdn.microsoft.com/en-us/library/aa394572%28v=vs.85%29.aspx

Possibly the most useful are the Win32 Computer System Hardware Classes. You can find information about those here:

http://msdn.microsoft.com/en-us/library/aa389273%28v=vs.85%29.aspx

Note: If you want to see all properties of a certain class, you can use an asterisk as a wild card. For instance, the following query will output all the properties of the Win32_Bios class:

Q: selects "* from Win32_Bios" of wmi

Next, since non-Windows computers and older windows comptuers may not have WMI, it's good form to use an If/Then/Else statement in the relevance to check for this:

Q: if (exists wmi) then (string value of selects "SerialNumber from Win32_Bios" of wmi) else "N/A"

Finally, if WMI is corrupt or broken on a computer, a WMI query may not work or could even cause problems on the system. Although these problems are very rare, it's a good idea to exercise some caution when making WMI queries. Also note that WMI is generally not available on Win9x computers or WinNT 4.0 computers.