Start-Process "firefox.exe" "www.google.com"
Start-Process "iexplore.exe" "www.google.com"
Start-Process "chrome.exe" "www.google.com"
#Or Use .Net API to open application
[System.Diagnostics.Process]::Start("firefox.exe","www.google.com")
[System.Diagnostics.Process]::Start("iexplore.exe","www.google.com")
[System.Diagnostics.Process]::Start("chrome.exe","www.google.com")