First find out where the Purge command lives. It will be in the Pro/E loadpoint\bin folder. On my system this is:
G:\Apps\PTC\proeWildfire4M170\bin

You need to add this to the Path environment variable.

Right click on "Computer" in the start menu and pick "properties"
Pick "Advanced system settings"
On the "Advanced" tap pick "Environment Variables"
Under "System variables" select "Path" then click "Edit"

This will give the paths the system searches to find executables. Don't mess it up! Each path value is separated by a semicolon (;).
It will open in an itty bitty non-resizable window (kind of makes you wonder how they could call the OS Windows, doesn't it?)
You may want to copy and paste it into a real text editor.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

thanks for the response.. it worked.

also, i tried copying the purge.exe to the working directory and it worked too.

The shell just has to be able to find the command. Copying every executable to the working directory is a rather brute force method.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.