How to list all properties of a PowerShell object

Try this:

Get-WmiObject -Class "Win32_computersystem" | Format-List *
Get-WmiObject -Class "Win32_computersystem" | Format-List -Property *

For certain objects, PowerShell provides a set of formatting instructions that can affect either the table or list formats. These are usually meant to limit the display of reams of properties down to just the essential properties. However there are times when you really want to see everything. In those cases Format-List * will show all the properties. Note that in the case where you're trying to view a PowerShell error record, you need to use "Format-List * -Force" to truly see all the error information, for example,

$error[0] | Format-List * -force

Note that the wildcard can be used like a traditional wilcard this:

Get-WmiObject -Class "Win32_computersystem" | Format-List M*

If you want to know what properties (and methods) there are:

Get-WmiObject -Class "Win32_computersystem" | Get-Member

You can also use:

Get-WmiObject -Class "Win32_computersystem" | Select *

This will show the same result as Format-List * used in the other answers here.