Q:

How can I set the PowerShell default window size in Windows 7? 

In Windows 7, how can I set the default PowerShell window size?  By default it comes up too tall for the netbook screen I am working with. 
I have tried the usual way of changing the size—by clicking in the upper-left corner and choosing “Properties”—but it tells me: Unable to modify the shortcut: .  Check to make sure it has not been deleted or renamed. ( yes, there is a dot in the middle of the error message)
I also tried right-clicking on the PowerShell shortcut in the Start menu and changing properties there, however, the changes don’t seem to stick. 

A:

Go Start -> All Programs -> Accessories -> Windows PowerShell.  RClick on the one you're using.  Go to the Layout tab, and change the settings you want. 

A:

Use a function like this in your profile (notepad $profile)
Function Set-WindowSize {
Param([int]$x=$host.ui.rawui.windowsize.width,
      [int]$y=$host.ui.rawui.windowsize.heigth)

    $size=New-Object System. Management. Automation. Host. Size($x,$y)
    $host.ui.rawui. WindowSize=$size   
}

Then call the function:
Set-WindowSize 100 50

A:

Another approach is to run Powershell as an administrator.   See How do I modify the Powershell console settings in Windows 7?