Hi, granogranalda. prafull suggested that you should copy all the files included in the Peops zip in your "plugins" directory,but I think only the .dll one is necessary, (I use only that file too - it works fine for me with my current PC). But since you already did that and did NOT work for you, I suspect that it may be a (very) rare case of incompatibility, or a very old video card.
...just for the record, I also tried Peops GPU with my old Pentium 200 (non-MMX), equipped with an old Viper 330 powered by the Riva 128 chip, and it also did NOT work...
...if a solution is not discovered soon, and you really need to use a soft plugin, may I suggest Pete's Soft GPU - it is very compatible and it is also "recognized" by my old P200...