How to tell a PC’s network link speed remotely

By using PowerShell like this:

Get-WmiObject -class Win32_PerfRawData_Tcpip_NetworkInterface -ComputerName Localhost | Format-Table Name,@{label="LinkSpeed(MB)";Expression={$_.CurrentBandwidth/1000000 -as [int]}}

which will return this:
Get Link Speed

I first learnt how to do this by reading this blog post by Dustin Hedges.