get Windows COmmander.
it's a file handlign system. Use it to navigate to the file syou want renamed, right click to highlight files (turns themr ed when you right click a file) then hit CTRL-M
Set the output to whatevertextyouwant-[C] or dont use the '-' it's up to you. On the right hand side choose the digits and voila. Hit start, then once done hit close and it's all done.
