Powershell invoked from c# is not listing all the files

Hi,

I'm trying to use lpr.exe which is available under %systemroot%.

I manually launch powershell  and cd to %systemroot% --> ls lp* --> it will list all the lpr.exe and associated files.

But, when I launch powershell through c# Process.Start --> a new powershell windows gets opened--> Cd to %systemroot% --> ls lp* -- its not listing the lpr.exe.

Please let me know If any one has come across this.

Thanks in advance