Many people still use telnet (client) for checking if port is open on remote host.
The Powershell cmdlet
Test-NetConnection is the new and improved tool for this and by creating a function alias in your profile settings you can have it easily available at any time without remembering the syntax.
1) Open Powershell profile
2) Add script
function open([string]$arg1, [int]$arg2)
Test-NetConnection -ComputerName $arg1 -Port $arg2 -InformationLevel Detailed
3) Save file and close/reopen the Powershell window
4) Test it in your powershell prompt by writing
open google.com 80